Section 1

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15. A net force is required to give an object with mass m an acceleration a. If a net force 6 is applied to an object with mass 2m, what is the acceleration on this object? A) 4 B) 6 C) 2 D) 3 E)

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Cards (203)

Section 1

(50 cards)

15. A net force is required to give an object with mass m an acceleration a. If a net force 6 is applied to an object with mass 2m, what is the acceleration on this object? A) 4 B) 6 C) 2 D) 3 E)

Front

a

Back

19. Which one of the following is not a unit of energy? A) kilowatt ⋅ hour B) newton ⋅ meter C) watt D) joule E) foot ⋅ pound

Front

c

Back

A 2.0-N force acts horizontally on a 10-N block that is initially at rest on a horizontal surface. The coefficient of static friction between the block and the surface is 0.50. 6. What is the magnitude of the frictional force that acts on the block? A) 5 N B) 10 N C) 2 N D) 0 N E) 8 N

Front

c

Back

16. Which one of the following choices is a vector quantity? A) volume B) mass C) displacement D) temperature E) time

Front

c

Back

A projectile fired from a gun has initial horizontal and vertical components of velocity equal to 30 m/s and 40 m/s, respectively. 1. What is the acceleration of the projectile when it reaches its maximum height? A) 9.8 m/s2, downward B) less than 9.8 m/s2 and non-zero. C) zero m/s2 D) Its magnitude is 9.8 m/s2; and its direction is changing. E) 4.9 m/s2, downward

Front

a

Back

A section of a river can be approximated as a rectangle that is 48 m wide and 172 m long. Express the area of this river in square kilometers. a) 8.26 × 10-3 km2 b) 8.26 km2 c) 8.26 × 103 km2 d) 3.58 km2 e) 3.58 × 10-2 km2

Front

a

Back

Complete the following statement: The ratio is equal to a) 102 b) 103 c) 106 d) 10-3 e) 10-6

Front

e

Back

. When we measure physical quantities, the units may be anything that is reasonable as long as they are well defined. It's usually best to use the international standard units. Density may be defined as the mass of an object divided by its volume. Which of the following units would probably not be acceptable units of density? a) gallons/liter b) kilograms/m3 c) pounds/ft3 d) slugs/yd3 e) grams/milliliter

Front

a

Back

15. Complete the following statement: The maximum speed at which a car can safely negotiate an unbanked curve depends on all of the following factors except A) the acceleration due to gravity. B) the coefficient of kinetic friction between the road and the tires. C) the ratio of the static frictional force between the road and the tires and the normal force exerted on the car. D) the coefficient of static friction between the road and the tires. E) the diameter of the curve.

Front

b

Back

12. Complete the following statement: The term net force most accurately describes A) the inertia of an object. B) the quantity that causes a displacement. C) the quantity that keeps an object moving. D) the quantity that changes the velocity of an object. E) the mass of an object

Front

d

Back

14. A football is kicked at an angle θ with respect to the horizontal. Which one of the following statements best describes the acceleration of the football during this event if air resistance is neglected? A) The acceleration is zero m/s2 when the football has reached the highest point in its trajectory. B) The acceleration is positive as the football rises, and it is negative as the football falls. C) The acceleration is 9.8 m/s2 at all times. D) The acceleration starts at 9.8 m/s2 and drops to some constant lower value as the ball approaches the ground. E) The acceleration is zero m/s2 at all times.

Front

c

Back

Express the following statement as an algebraic expression: "There are 264 gallons in a one cubic meter container." Let G represent the number of gallons and M represent the number of one cubic meter containers. a) G = 264M b) G = M/264 c) G = 0.00379M d) M = G/264 e) M = G

Front

a

Back

18. Which force is responsible for holding a car in an unbanked curve? A) the reaction force to the car's weight B) the vertical component of the normal force C) the horizontal component of the normal force D) the car's weight E) the force of friction

Front

e

Back

. If one inch is equal to 2.54 cm, express 9.68 inches in meters. a) 0.262 m b) 0.0381 m c) 0.0508 m d) 0.114 m e) 0.246 m

Front

e

Back

A 2400-kg satellite is in a circular orbit around a planet. The satellite travels with a constant speed of 6670 m/s. The radius of the circular orbit is 8.92 × 106 m. 7. At the instant shown in the figure, which arrow indicates the direction of the net force on the satellite?

Front

a

Back

17. Two identical blocks are pulled along a rough surface as suggested in the figure. Which one of the following statements is false? rectangle up > square > A) A force of the same magnitude was required to start each block moving. B) The coefficient of kinetic friction is the same in each case. C) The normal force exerted on the blocks by the surface is the same for both blocks. D) The magnitude of the force of kinetic friction is greater for the block on the right. E) A force of the same magnitude is needed to keep each block moving.

Front

d

Back

. Given that one inch is equal to 25.4 mm. How many feet equal 21 m? a) 53.0 ft b) 82.7 ft c) 63.0 ft d) 68.9 ft e) 47.9 ft

Front

d

Back

5. In which one of the following situations does the car have a westward acceleration? A) The car starts from rest and moves toward the east. B) The car travels westward at constant speed. C) The car travels eastward and slows down. D) The car travels eastward and speeds up. E) The car travels westward and slows down.

Front

a

Back

18. For which one of the following situations will the path length equal the magnitude of the displacement? A) A train travels 5 miles east before it stops. It then travels 2 miles west. B) A ball on the end of a string is moving in a vertical circle. C) A ball is rolling down an inclined plane. D) A toy train is traveling around a circular track. E) A ball rises and falls after being thrown straight up from the earth's surface.

Front

c

Back

13. Which one of the following is an SI base unit? A) slug B) centimeter C) kilogram D) newton E) gram

Front

...d

Back

A 1500-kg vehicle travels at a constant speed of 22 m/s around a circular track that has a radius of 85 m. 10. What is the magnitude of the acceleration of the vehicle? A) 0.26 m/s2 B) 9.8 m/s2 C) zero m/s2 D) 5.7 m/s2 E) 1.2 m/s2

Front

d

Back

A horse pulls a cart along a flat road. Consider the following four forces that arise in this situation. (1) the force of the horse pulling on the cart (3) the force of the horse pushing on the road (2) the force of the cart pulling on the horse (4) the force of the road pushing on the horse 10. Which two forces form an "action-reaction" pair that obeys Newton's third law? A) 2 and 4 B) 3 and 4 C) 1 and 3 D) 2 and 3 E) 1 and 4

Front

d

Back

A car starts from rest on a circular track with a radius of 150 m. Relative to the starting position, what angle has the car swept out when it has traveled 150 m along the circular track? a) 1 radian b) pi/2 radians c) pi radians d) 3pi/2 radians e) 2pi radians

Front

a

Back

5. Which one of the following choices is an example of a non-conservative force? A) kinetic frictional force B) gravitational force C) elastic spring force D) electrical force

Front

a

Back

12. In which one of the following systems is there a decrease in gravitational potential energy? A) a car ascends a steep hill B) a boy stretches a horizontal spring C) water is forced upward through a pipe D) a crate rests at the bottom of an inclined plane E) a girl jumps down from a bed

Front

e

Back

1. The kinetic energy of a car is 8 × 106 J as it travels along a horizontal road. How much work is required to stop the car in 10 s? A) 8 × 106 J B) 8 × 105 J C) zero joules D) 8 × 107 J E) 8 × 104 J

Front

a

Back

Approximately how many seconds are there in a century? a) 86 400 s b) 5.0 × 106 s c) 3.3 × 1018 s d) 3.2 × 109 s e) 8.6 × 104 s

Front

d

Back

3. A car travels in a straight line covering a total distance of 90.0 miles in 60.0 minutes. Which one of the following statements concerning this situation is necessarily true? A) The average velocity of the car is 90.0 miles per hour in the direction of motion. B) The first 45 miles must have been covered in 30.0 minutes. C) The speed of the car must be 90.0 miles per hour throughout the entire trip. D) The velocity of the car is constant. E) The acceleration of the car must be non-zero.

Front

a

Back

During a one-hour trip, a small boat travels 80.0 km north and then travels 60.0 km east. 9. What is the boat's displacement for the one-hour trip? A) 280 km B) 140 km C) 10 000 km D) 100 km E) 20 km

Front

c

Back

19. What is the angle between the vectors A and -A when they are drawn from a common origin? A) 90° B) 270° C) 0° D) 360° E) 180°

Front

a

Back

7. In the process of delivering mail, a postal worker walks 161 m, due east from his truck. He then turns around and walks 194 m, due west from his truck. What is the worker's displacement relative to his truck? A) 33 m, due east B) 194 m, due west C) 252 m, due east D) 355 m, due west E) 33 m, due west

Front

a

Back

2. At what angle is the projectile fired (measured with respect to the horizontal)? A) 45° B) 37° C) 60° D) 40° E) 53°

Front

a

Back

Given the mathematical expression A = 3B, determine which of the following statements is true. a) The ratio B/A = 3. b) A is three times smaller than B. c) The ratio A/B = 1/3. d) B is three times smaller than A. e) A and B can have any value. There is no relationship between them.

Front

d

Back

Given the following equation: y = cnat2, where n is an integer with no units, c is a number between zero and one with no units, the variable t has units of seconds and y is expressed in meters, determine which of the following statements is true. a) Through dimensional analysis, a has units of meters per second (m/s) and n =1. b) Through dimensional analysis, a has units of meters per second (m/s) and n =2. c) Through dimensional analysis, a has units of meters per second per second (m/s2) and n =1. d) Through dimensional analysis, a has units of meters per second per second (m/s2) and n =2. e) a has units of meters per second per second (m/s2), but value of n cannot be determined through dimensional analysis.

Front

e

Back

9. The kinetic energy of a car is 8 × 106 J as it travels along a horizontal road. How much power is required to stop the car in 10 s? A) 8 × 104 W B) 8 × 106 W C) 8 × 107 W D) 8 × 105 W E) zero watts

Front

d

Back

. A glacier is receding at a constant rate of 0.4 cm per day. After 3.0 years, by what length has the glacier receded? Express your answer in meters. a) 17.1 m b) 4.38 m c) 9.82 m d) 1.46 m e) 12.7 m

Front

b

Back

3. A solar-powered car is traveling at constant speed around a circular track. What happens to the centripetal acceleration of the car if the speed is doubled? A) The centripetal acceleration increases by a factor of 4. B) The centripetal acceleration remains the same. C) The centripetal acceleration is decreased by a factor of one-half. D) The centripetal acceleration is decreased by a factor of one-fourth. E) The centripetal acceleration increases by a factor of 2.

Front

a

Back

4. Which one of the following situations is an example of an object with a non-zero kinetic energy? A) a stationary pendulum B) a satellite in geosynchronous orbit C) a boulder resting at the bottom of a cliff D) a drum of diesel fuel on a parked truck E) a car parked at the top of a hill

Front

b

Back

17. A body initially at rest is accelerated at a constant rate for 5.0 seconds in the positive x direction. If the final speed of the body is 20.0 m/s, what was the body's acceleration? A) 9.8 m/s2 B) 1.6 m/s2 C) 2.0 m/s2 D) 4.0 m/s2 E) 0.25 m/s2

Front

a

Back

16. A rock is suspended from a string and moves downward at constant speed. Which statement is true concerning the tension in the string if air resistance is ignored? A) The tension points downward. B) The tension is less than the weight of the rock. C) The tension is greater than the weight of the rock. D) The tension is equal to the weight of the rock. E) The tension is zero newtons.

Front

d

Back

. The radius of sphere A is one half that of sphere B. How do the circumference and volume of sphere B compare to sphere A? a) The circumference of B is 2 times that of A; and its volume is 4 times that of A. b) The circumference of B is 2 times that of A; and its volume is 6 times that of A. c) The circumference of B is 2 times that of A; and its volume is 8 times that of A. d) The circumference of B is 4 times that of A; and its volume is 6 times that of A. e) The circumference of B is 4 times that of A; and its volume is 8 times that of A.

Front

c

Back

8. A displacement vector has a magnitude of 810 m and points at an angle of 18° above the positive x axis. What are the x and y scalar components of this vector? x scalar component y scalar component A) 250 m 750 m B) 770 m 250 m C) 560 m 585 m D) 713 m 385 m E) 585 m 560 m

Front

a

Back

20. In which one of the following situations will there be an increase in kinetic energy? A) A stone at the end of a string is whirled in a horizontal circle at constant speed. B) A satellite travels in a circular orbit around the earth at fixed altitude. C) A ball starts from rest and freely rolls downhill. D) A projectile approaches its maximum height. E) A box is pulled across a rough floor at constant speed.

Front

c

Back

11. Which one of the following terms is used to indicate the natural tendency of an object to remain at rest or in motion at a constant speed along a straight line? A) acceleration B) equilibrium C) inertia D) force E) velocity

Front

...b

Back

8. A 44-kg child steps onto a scale and the scale reads 430 N. What is the magnitude of the normal force acting on the child? A) 215 N B) 860 N C) 44 N D) 430 N E) 645 N

Front

d

Back

2. A 2.0-N rock slides on a frictionless inclined plane. Which one of the following statements is true concerning the normal force that the plane exerts on the rock? A) It increases as the angle of inclination, θ, is increased. B) The normal force is greater than 2.0 N. C) The normal force is zero newtons. D) The normal force is less than 2.0 N, but greater than zero newtons. E) The normal force is 2.0 N.

Front

d

Back

20. A passenger at rest on a flatbed train car fires a bullet straight up. The event is viewed by observers at rest on the station platform as the train moves past the platform with constant velocity. What is the trajectory of the bullet as described by the observers on the platform? A) a circular path centered on the gun B) a straight horizontal path in the direction of the train's velocity C) a parabolic path D) a straight vertical path up and down E) a straight diagonal path

Front

d

Back

6. A ball is thrown vertically upward from the surface of the earth. Consider the following quantities: (1) the speed of the ball; (2) the velocity of the ball; (3) the acceleration of the ball. Which of these is (are) zero when the ball has reached the maximum height? A) 1 only B) 1 and 2 only C) 1, 2, and 3 D) 1 and 3 only E) 2 only

Front

a

Back

14. A spaceship is in orbit around the earth at an altitude of 12 000 miles. Which one of the following statements best explains why the astronauts experience "weightlessness?" A) The force of the earth on the spaceship and the force of the spaceship on the earth cancel because they are equal in magnitude but opposite in direction. B) The force of gravity decreases as the inverse square of the distance from the earth's center. C) The pull of the earth on the spaceship is canceled by the pull of the other planets. D) The centripetal force of the earth on the astronaut in orbit is zero newtons. E) The spaceship is in free fall and its floor cannot press upwards on the astronauts.

Front

e

Back

11. Which force is responsible for holding a car in a frictionless banked curve? A) the vertical component of the normal force B) the horizontal component of the car's weight C) the horizontal component of the normal force D) the reaction force to the car's weight E) the vertical component of the car's weight

Front

c

Back

Section 2

(50 cards)

. An object is moving due south at a constant velocity. Then, a net force directed due west acts on the object for a short time interval, after which, the net force on the object is zero newtons. Which one of the following statements concerning the object is necessarily true? a) The final velocity of the object will be directed south of west. b) The final velocity of the object will be directed due south. c) The direction of acceleration of the object while the force was being applied was south of west. d) The magnitude of the object's acceleration while the force was being applied was dependent on the object's initial velocity. e) The change in the object's velocity while the force was applied was directed south of east.

Front

a

Back

Complete the following statement: For an object moving with a negative velocity and a positive acceleration, the distance traveled a) increases for each second that the object moves. b) is the same regardless of the time that the object moves. c) is the same for each second that the object moves. d) cannot be determined, even if the elapsed time is known. e) decreases for each second that the object moves.

Front

e

Back

An airplane is flying horizontally at a constant velocity when a package is dropped from its cargo bay. Assuming no air resistance, which one of the following statements is correct? a) The package follows a curved path that lags behind the airplane. b) The package follows a straight line path that lags behind the airplane. c) The package follows a straight line path, but it is always vertically below the airplane. d) The package follows a curved path, but it is always vertically below the airplane. e) The package follows a curved path, but its horizontal position varies depending on the velocity of the airplane.

Front

d

Back

. Determine the angle in the right triangle shown. | \ | \ .5m| \ |_______\ .7m a) 54.5 b) 62.0 c) 35.5 d) 28.0 e) 41.3

Front

c

Back

Jackson heads east at 25 km/h for 20 minutes before heading south at 45 km/h for 20 minutes. Hunter heads south at 45 km/h for 10 minutes before heading east at 25 km/h for 30 minutes. Which driver has the greater average velocity, if either? a) Jackson b) Hunter c) They both have the same average velocity.

Front

a

Back

A turtle and a rabbit are to have a race. The turtle's average speed is 0.9 m/s. The rabbit's average speed is 9 m/s. The distance from the starting line to the finish line is 1500 m. The rabbit decides to let the turtle run before he starts running to give the turtle a head start. What, approximately, is the maximum time the rabbit can wait before starting to run and still win the race? a) 15 minutes b) 18 minutes c) 20 minutes d) 22 minutes e) 25 minutes

Front

e

Back

The city of Denver is located approximately one mile (1.61 km) above sea level. Assume you are standing on a beach in Los Angeles, California, at sea level; estimate the angle of the resultant vector with respect to the horizontal axis between your location in California and Denver. a) between 1 and 2 b) between 0.5 and 0.9 c) between 0.11 and 0.45 d) between 0.06 and 0.10 e) less than 0.05

Front

d

Back

An eagle takes off from a tree branch on the side of a mountain and flies due west for 225 m in 19 s. Spying a mouse on the ground to the west, the eagle dives 441 m at an angle of 65 relative to the horizontal direction for 11 s to catch the mouse. Determine the eagle's average velocity for the thirty second interval. a) 19 m/s at 44 below the horizontal direction b) 22 m/s at 65 below the horizontal direction c) 19 m/s at 65 below the horizontal direction d) 22 m/s at 44 below the horizontal direction e) 25 m/s at 27 below the horizontal direction

Front

a

Back

Complete the following statement: In two-dimensional motion in the x-y plane, the x part of the motion and the y part of the motion are independent a) only if there is no acceleration in either direction. b) only if there is no acceleration in one of the directions. c) only if there is an acceleration in both directions. d) whether or not there is an acceleration in any direction. e) whenever the acceleration is in the y direction only.

Front

d

Back

Jake bought a new dog and is carrying a new dog house on the flatbed of his brand new pickup truck. Jake isn't sure if he should tie the house down, but he doesn't want it to scratch the paint if it should slide during braking. During the trip home, Jake will travel along straight, level roads and have to stop from a maximum speed of 21 m/s in a distance of 29 m. What is the minimum coefficient of static friction between the dog house and the paint that is required to prevent it from sliding? Compare your answer to the actual coefficient of friction of 0.35 to determine if the dog house should be tied down. a) 0.22, no need to tie the house down b) 0.30, no need to tie the house down c) 0.35, he may want to tie it down just in case d) 0.56, the house needs to be tied down e) 0.78, the house needs to be tied down

Front

e

Back

A race car, traveling at constant speed, makes one lap around a circular track of radius r in a time t. The circumference of a circle is given by C = 2pir. Which one of the following statements concerning this car is true? a) The displacement of the car does not change with time. b) The instantaneous velocity of the car is constant. c) The average speed of the car is the same over any time interval. d) The average velocity of the car is the same over any time interval. e) The average speed of the car over any time interval is equal to the magnitude of the average velocity over the same time interval.

Front

c

Back

. During the execution of a play, a football player carries the ball for a distance of 33 m in the direction 76° north of east. To determine the number of meters gained on the play, find the northward component of the ball's displacement. a) 8.0 m b) 16 m c) 24 m d) 28 m e) 32 m

Front

e

Back

. In two-dimensional motion in the x-y plane, what is the relationship between the x part of the motion to the y part of the motion? a) The x part of the motion is independent of the y part of the motion. b) The y part of the motion goes as the square of the x part of the motion. c) The x part of the motion is linearly dependent on the y part of the motion. d) The x part of the motion goes as the square of the y part of the motion. e) If the y part of the motion is in the vertical direction, then x part of the motion is dependent on the y part.

Front

a

Back

Consider each of the following comparisons between various length units. Which one of these comparisons is false? a) 1 m > 10 cm b) 1000 nm < 1 mm c) 1 foot < 10 cm d) 1 mile > 1 km e) 10 inches < 1 m

Front

c

Back

Two satellites of masses m and 2m are at opposite sides of the same circular orbit about the Earth. Which one of the following statements is true? a) The magnitude of the gravitational force is greater for the satellite of mass 2m than it is for the other satellite. b) The magnitude of the gravitational force is the same for both satellites; and it is greater than zero newtons. c) Since the satellites are moving at a constant velocity, the gravitational force on the satellites must be zero newtons. d) The magnitude of the gravitational force is greater for the satellite of mass m than it is for the other satellite. e) The satellite of mass 2m must move faster in the orbit than the other and eventually they will be on the same side of the Earth.

Front

a

Back

Two cars travel along a level highway. An observer notices that the distance between the cars is increasing. Which one of the following statements concerning this situation is necessarily true? a) Both cars could be accelerating at the same rate. b) The leading car has the greater acceleration. c) The trailing car has the smaller acceleration. d) The velocity of each car is increasing. e) At least one of the cars has a non-zero acceleration.

Front

a

Back

. At one particular moment, a subway train is moving with a positive velocity and negative acceleration. Which of the following phrases best describes the motion of this train? Assume the front of the train is pointing in the positive x direction. a) The train is moving forward as it slows down. b) The train is moving in reverse as it slows down. c) The train is moving faster as it moves forward. d) The train is moving faster as it moves in reverse. e) There is no way to determine whether the train is moving forward or in reverse.

Front

a

Back

A bicyclist is riding at a constant speed along a horizontal, straight-line path. The rider throws a ball straight up to a height a few meters above her head. Ignoring air resistance, where will the ball land? Ignore any effects of air resistance. a) in front of the rider b) behind the rider c) in the same hand that threw the ball d) in the opposite hand to the one that threw it e) This cannot be determined without knowing the speed of the rider and the maximum height of the ball.

Front

c

Back

In the morning, a bird is in Tampa, Florida. In the afternoon, the bird is near Orlando, Florida. Given this information, which one of the following statements best describes the relationship between the magnitude of the bird's displacement and the distance the bird traveled? a) The distance traveled is either greater than or equal to the magnitude of bird's displacement. b) The distance traveled is either less than or equal to the magnitude of bird's displacement. c) The distance traveled is equal to the magnitude of bird's displacement. d) The distance traveled is either less than or greater than the magnitude of bird's displacement. e) The distance traveled is greater than the magnitude of bird's displacement.

Front

a

Back

An airplane starts from rest at the end of a runway and accelerates at a constant rate. In the first second, the airplane travels 1.11 m. What is the speed of the airplane at the end of the second second? a) 1.11 m/s b) 2.22 m/s c) 3.33 m/s d) 4.44 m/s e) 5.55 m/s

Front

d

Back

. Complete the following statement: For an object moving at constant acceleration, the distance traveled a) increases for each second that the object moves. b) is the same regardless of the time that the object moves. c) is the same for each second that the object moves. d) cannot be determined, even if the elapsed time is known. e) decreases for each second that the object moves.

Front

a

Back

Two objects that may be considered point masses are initially separated by a distance d. The separation distance is then decreased to d/3. How does the gravitational force between these two objects change as a result of the decrease? a) The force will not change since it is only dependent on the masses of the objects. b) The force will be nine times larger than the initial value. c) The force will be three times larger than the initial value. d) The force will be one third of the initial value. e) The force will be one ninth of the initial value.

Front

b

Back

A ball is thrown toward a wall, bounces, and returns to the thrower with the same speed as it had before it bounced. Which one of the following statements correctly describes this situation? a) The ball was not accelerated during its contact with the wall because its speed remained constant. b) The instantaneous velocity of the ball from the time it left the thrower's hand was constant. c) The only time that the ball had an acceleration was when the ball started from rest and left the hand of the thrower and again when the ball returned to the hand and was stopped. d) During this situation, the ball was never accelerated. e) The ball was accelerated during its contact with the wall because its direction changed.

Front

e

Back

. A child is driving a bumper car at an amusement park. During one interval of the ride, she is traveling at the car's maximum speed when she crashes into a bumper attached to one of the side walls. During the collision, her glasses fly forward from her face. Which of the following statements best describes why the glasses flew from her face? a) The glasses continued moving forward because there was too little force acting on them to hold them on her face during the collision. b) During the collision, the girl's face pushed the glasses forward. c) The glasses continued moving forward because the force of the air on them was less than the force of the girl's face on them. d) During the collision, the car pushed the girl forward causing her glasses to fly off her face. e) During the collision, the wall pushed the car backward and the girl reacted by pushing her glasses forward.

Front

a

Back

. Two identical ping-pong balls are selected for a physics demonstration. A tiny hole is drilled in one of the balls; and the ball is filled with water. The hole is sealed so that no water can escape. The two balls are then dropped from rest at the exact same time from the roof of a building. Assuming there is no wind, which one of the following statements is true? a) The two balls reach the ground at the same time. b) The heavier ball reaches the ground a long time before the lighter ball. c) The heavier ball reaches the ground just before the lighter ball. d) The heavier ball has a much larger velocity when it strikes the ground than the light ball. e) The heavier ball has a slightly larger velocity when it strikes the ground than the light ball.

Front

a

Back

. A truck drives due south for 1.2 km in 1.5 minutes. Then, the truck turns and drives 1.2 km due west for 1.5 minutes. Which one of the following statements is correct? a) The average speed for the two segments is the same. The average velocity for the two segments is the same. b) The average speed for the two segments is not the same. The average velocity for the two segments is the same. c) The average speed for the two segments is the same. The average velocity for the two segments is not the same. d) The average speed for the two segments is not the same. The average velocity for the two segments is not the same.

Front

c

Back

On a rainy evening, a truck is driving along a straight, level road at 25 m/s. The driver panics when a deer runs onto the road and locks the wheels while braking. If the coefficient of friction for the wheel/road interface is 0.68, how far does the truck slide before it stops? a) 55 m b) 47 m c) 41 m d) 36 m e) 32 m

Front

b

Back

Which one of the following situations involves a vector? a) The submarine followed the coastline for 35 kilometers. b) The air temperature in Northern Minnesota dropped to 4 C. c) The Hubble Telescope orbits 598 km above the surface of the earth. d) The baseball flew into the dirt near home plate at 44 m/s. e) The flock of Canadian Geese was spotted flying due south at 5 m/s.

Front

e

Back

. A cannon directed straight upward launches a ball with an initial speed v. The ball reaches a maximum height h in a time t. Then, the same cannon is used to launch a second ball straight upward at a speed 2v. In terms of h and t, what is the maximum height the second ball reaches and how long does it take to reach that height? Ignore any effects of air resistance. a) 2h, t b) 4h, 2t c) 2h, 4t d) 2h, 2t e) h, t

Front

b

Back

A car of mass m is moving at a speed 3v in the left lane on a highway. In the right lane, a truck of mass 3m is moving at a speed v. As the car is passing the truck, the driver notices that the traffic light ahead has turned yellow. Both drivers apply the brakes to stop ahead. What is the ratio of the force required to stop the truck to that required to stop the car? Assume each vehicle stops with a constant deceleration and stops in the same distance x. a) 1/9 b) 1/3 c) 1 d) 3 e) 9

Front

b

Back

An astronaut is on a spacewalk outside her ship in "gravity-free" space. Initially, the spacecraft and astronaut are at rest with respect to each other. Then, the astronaut pushes to the left on the spacecraft and the astronaut accelerates to the right. Which one of the following statements concerning this situation is true? a) The astronaut stops moving after she stops pushing on the spacecraft. b) The velocity of the astronaut increases while she is pushing on the spacecraft. c) The force exerted on the astronaut is larger than the force exerted on the spacecraft. d) The spacecraft does not move, but the astronaut moves to the right with a constant speed. e) The force exerted on the spacecraft is larger than the force exerted on the astronaut.

Front

b

Back

Some children are pulling on a rope that is raising a bucket via a pulley up to their tree house. The bucket containing their lunch is rising at a constant velocity. Ignoring the mass of the rope, but not ignoring air resistance, which one of the following statements concerning the tension in the rope is true? a) The magnitude of the tension is zero newtons. b) The direction of the tension is downward. c) The magnitude of the tension is equal to that of the weight of the bucket. d) The magnitude of the tension is less than that of the weight of the bucket. e) The magnitude of the tension is greater than that of the weight of the bucket.

Front

e

Back

An astronaut, whose mass on the surface of the Earth is m, orbits the Earth in the space shuttle at an altitude of 450 km. What is her mass while orbiting in the space shuttle? a) 0.125m b) 0.25m c) 0.50m d) 0.75m e) m

Front

e

Back

. A rock is suspended from a string. Barbara accelerates the rock upward with a constant acceleration by pulling on the other end of the string. Which one of the following statements concerning the tension in the string is true? a) The tension is independent of the magnitude of the rock's acceleration. b) The magnitude of the tension is equal to the weight of the rock. c) The magnitude of the tension is less than the weight of the rock. d) The magnitude of the tension is greater than the weight of the rock. e) The tension decreases as the speed of the rock increases as it rises

Front

d

Back

A car is driving due south through a parking lot and its speed is monitored. Prepare a graph of the car's speed versus time using the following data: Segment A: the car begins at rest and uniformly accelerates to 5 m/s in an elapsed time of 2 s. Segment B: for the next 10 seconds, the car moves at a constant speed of 5 m/s. Segment C: during the next 2 seconds, the car uniformly slows to 3 m/s. Segment D: for the next 4 seconds, the car travels at a constant speed of 3 m/s. Using your graph, determine which one of the following statements is false. a) Net forces act on the car during intervals A and C. b) No net force acts on the car during interval B. c) Opposing forces may be acting on the car during interval C. d) The magnitude of the net force acting during interval A is less than that during C. e) Opposing forces may be acting on the car during interval B.

Front

d

Back

. A water skier is being pulled by a rope attached to a speed boat moving at a constant velocity. Consider the following four forces: (1) the force of the boat pulling the rope, (2) the force of the skier pulling on the rope, (3) the force of the boat pushing the water, and (4) the force of the water pushing on the boat. Which two forces are an "action-reaction" pair that is consistent with Newton's third law of motion? a) 1 and 2 b) 2 and 3 c) 2 and 4 d) 3 and 4 e) 1 and 4

Front

d

Back

An airplane starts from rest at the end of a runway and accelerates at a constant rate. In the first second, the airplane travels 1.11 m. How much additional distance will the airplane travel during the second second of its motion? a) 1.11 m b) 2.22 m c) 3.33 m d) 4.44 m e) 5.55 m

Front

c

Back

If an object is moving can you conclude there are forces acting on it? If an object is at rest, can you conclude there are no forces acting on it? Consider each of the following situations. In which one of the following cases, if any, are there no forces acting on the object? a) A bolt that came loose from a satellite orbits the earth at a constant speed. b) After a gust of wind has blown through a tree, an apple falls to the ground. c) A man rests by leaning against a tall building in downtown Dallas. d) Sometime after her parachute opened, the sky diver fell toward the ground at a constant velocity. e) Forces are acting on all of the objects in choices a, b, c, and d.

Front

e

Back

An object moves horizontally with a constant acceleration. At time t = 0 s, the object is at x = 0 m. For which of the following combinations of initial velocity and acceleration will the object be at x = -1.5 m at time t = 3 s? a) v0 = +2 m/s, a = +2 m/s b) v0 = -2 m/s, a = +2 m/s c) v0 = +2 m/s, a = -2 m/s d) v0 = -2 m/s, a = -2 m/s e) v0 = +1 m/s, a = -1 m/s

Front

e

Back

. Packages A and B are dropped from the same height simultaneously. Package A is dropped from an airplane that is flying due east at constant speed. Package B is dropped from rest from a helicopter hovering in a stationary position above the ground. Ignoring air friction effects, which of the following statements is true? a) A and B reach the ground at the same time, but B has a greater velocity in the vertical direction. b) A and B reach the ground at the same time; and they have the same velocity in the vertical direction. c) A and B reach the ground at different times because B has a greater velocity in both the horizontal and vertical directions. d) A and B reach the ground at different times; and they have the same velocity in the vertical direction. e) A reaches the ground first because it falls straight down, while B has to travel much further than A.

Front

b

Back

. One end of a string is tied to a tree branch at a height h above the ground. The other end of the string, which has a length L = h, is tied to a rock. The rock is then dropped from the branch. Which one of the following statements concerning the tension in the string is true as the rock falls? a) The tension is independent of the magnitude of the rock's acceleration. b) The magnitude of the tension is equal to the weight of the rock. c) The magnitude of the tension is less than the weight of the rock. d) The magnitude of the tension is greater than the weight of the rock. e) The tension increases as the speed of the rock increases as it falls.

Front

c

Back

In an air race, two planes are traveling due east. Plane One has a larger acceleration than Plane Two has. Both accelerations are in the same direction. Which one of the following statements is true concerning this situation? a) In the same time interval, the change in the velocity of Plane Two is greater than that of Plane One. b) In the same time interval, the change in the velocity of Plane One is greater than that of Plane Two. c) Within the time interval, the velocity of Plane Two remains greater than that of Plane One. d) Within the time interval, the velocity of Plane One remains greater than that of Plane Two. e) Too little information is given to compare the velocities of the planes or how the velocities are changing.

Front

b

Back

. A 912-kg car is being driven down a straight, level road at a constant speed of 31.5 m/s. When the driver sees a police cruiser ahead, she removes her foot from the accelerator. After 8.00 s, the speed of the car is 24.6 m/s, which is the posted speed limit. What is the magnitude of the average net force acting on the car during the 8.00 s interval? a) 55.2 N b) 445 N c) 629 N d) 787 N e) 864 N

Front

d

Back

. A large crate is lifted vertically at constant speed by a rope attached to a helicopter. Consider the following four forces that arise in this situation: (1) the weight of the helicopter, (2) the weight of the crate, (3) the force of the crate pulling on the earth, and (4) the force of the helicopter pulling on the rope. Which one of the following relationships concerning the forces or their magnitudes is correct? a) The magnitude of force 4 is greater than that of force 2. b) The magnitude of force 4 is greater than that of force 1. c) Forces 3 and 4 are equal in magnitude, but oppositely directed. d) Forces 2 and 4 are equal in magnitude, but oppositely directed. e) The magnitude of force 1 is less than that of force 2.

Front

d

Back

Starting from rest, two objects accelerate with the same constant acceleration. Object A accelerates for three times as much time as object B, however. Which one of the following statements is true concerning these objects at the end of their respective periods of acceleration? a) Object A will travel three times as far as object B. b) Object A will travel nine times as far as object B. c) Object A will travel eight times as far as object B. d) Object A will be moving 1.5 times faster than object B. e) Object A will be moving nine times faster than object B.

Front

b

Back

Football A is kicked at a speed v at an angle of theta with respect to the horizontal direction. If football B is kicked at the same angle, but with a speed 2v, what is the ratio of the range of B to the range of A? a) 1 b) 2 c) 3 d) 4 e) 9

Front

d

Back

A physics student standing on the edge of a cliff throws a stone vertically downward with an initial speed of 10.0 m/s. The instant before the stone hits the ground below, it is traveling at a speed of 30.0 m/s. If the physics student were to throw the rock horizontally outward from the cliff instead, with the same initial speed of 10.0 m/s, what is the magnitude of the velocity of the stone just before it hits the ground? Ignore any effects of air resistance. a) 10.0 m/s b) 20.0 m/s c) 30.0 m/s d) 40.0 m/s e) The height of the cliff must be specified to answer this question.

Front

c

Back

. During a high school track meet, an athlete performing the long jump runs and leaps at an angle of 25 degrees and lands in a sand pit 8.5 m from his launch point. If the launch point and landing points are at the same height, y = 0 m, with what speed does the athlete land? a) 6 m/s b) 8 m/s c) 10 m/s d) 2 m/s e) 4 m/s

Front

c

Back

In making a movie, a stuntman has to jump from one roof onto another roof, located 2.0 m below. The buildings are separated by a distance of 2.5 m. What is the minimum horizontal speed that the stuntman must have when jumping from the first roof to have a successful jump? a) 3.9 m/s b) 2.5 m/s c) 4.3 m/s d) 4.5 m/s e) 3.1 m/s

Front

a

Back

Which one of the following statements is true concerning scalar quantities? a) Scalar quantities must be represented by base units. b) Scalar quantities have both magnitude and direction. c) Scalar quantities can be added to vector quantities using rules of trigonometry. d) Scalar quantities can be added to other scalar quantities using rules of trigonometry. e) Scalar quantities can be added to other scalar quantities using rules of ordinary addition.

Front

e

Back

Section 3

(50 cards)

. A football of mass m, initially at rest, is kicked so that leaves the foot at a speed v. If t represents the duration of the collision between the ball and the foot, which one of the following expressions determines the magnitude of the average force exerted on the ball? a) mvt b) (1/2)mv2 c) (1/2)mv2/t d) mv/t e) (1/2)mvt2

Front

d

Back

A high school baseball pitcher can typically throw a ball at 22 m/s. Professional baseball pitchers can throw the ball with twice that speed, but few others can. To see why this is the case, determine the difference in the kinetic energy of a baseball thrown at v m/s and one thrown at 2v m/s and express the difference as a percentage. a) 50 % b) 100 % c) 200 % d) 300 % e) 400 %

Front

d

Back

Imagine you are swinging a bucket by the handle around in a circle that is nearly level with the ground (a horizontal circle). What is the force, the physical force, holding the bucket in a circular path? a) the centripetal force b) the centrifugal force c) your hand on the handle d) gravitational force e) None of the above are correct.

Front

c

Back

Consider the following: (i) the book is at rest, (ii) the book is moving at a constant velocity, (iii) the book is moving with a constant acceleration. Under which of these conditions is the book in equilibrium? a) (i) only b) (ii) only c) (iii) only d) (i) and (ii) only e) (ii) and (iii) only

Front

d

Back

. After an ice storm, ice falls from one of the top floors of a 65-story building. The ice falls freely under the influence of gravity. Which one of the following statements concerning this situation is true? a) The kinetic energy of the ice increases by equal amounts for equal distances. b) The kinetic energy of the ice increases by equal amounts for equal times. c) The potential energy of the ices decreases by equal amounts for equal times. d) The total energy of the block increases by equal amounts over equal distances. e) As the block falls, the net work done by all of the forces acting on the ice is zero joules.

Front

a

Back

. An elevator supported by a single cable descends a shaft at a constant speed. The only forces acting on the elevator are the tension in the cable and the gravitational force. Which one of the following statements is true? a) The work done by the tension force is zero joules. b) The net work done by the two forces is zero joules. c) The work done by the gravitational force is zero joules. d) The magnitude of the work done by the gravitational force is larger than that done by the tension force. e) The magnitude of the work done by the tension force is larger than that done by the gravitational force.

Front

c

Back

Which of the following parameters determine how fast you need to swing a water bucket vertically so that water in the bucket will not fall out? a) radius of swing b) mass of bucket c) mass of water d) a and b e) a and c

Front

a

Back

A space probe is orbiting a planet on a circular orbit of radius R and a speed v. The acceleration of the probe is a. Suppose rockets on the probe are fired causing the probe to move to another circular orbit of radius 0.5R and speed 2v. What is the magnitude of the probe's acceleration in the new orbit? a) a/2 b) a c) 2a d) 4a e) 8a

Front

e

Back

Imagine you are swinging a bucket by the handle around in a circle that is nearly level with the ground (a horizontal circle). Now imagine there's a ball in the bucket. What keeps the ball moving in a circular path? a) contact force of the bucket on the ball b) contact force of the ball on the bucket c) gravitational force on the ball d) the centripetal force e) the centrifugal force

Front

a

Back

A ball on the end of a rope is moving in a vertical circle near the surface of the earth. Point A is at the top of the circle; C is at the bottom. Points B and D are exactly halfway between A and C. Which one of the following statements concerning the tension in the rope is true? a) The tension is the same at points A and C. b) The tension is smallest at point C. c) The tension is smallest at both points B and D. d) The tension is smallest at point A. e) The tension is the same at all four points.

Front

d

Back

In a moving elevator, a woman standing on a bathroom scale notices that the reading on the scale is significantly larger than when the elevator was at rest. The elevator itself only has two forces acting on it: the tension in a cable and the force of gravity. Which one of the following statements is false concerning this situation? a) The elevator is uniformly accelerating. b) The elevator's speed is increasing as it moves upward. c) The tension in the cable exceeds the weight of the elevator and its contents. d) The elevator could be moving upward at constant speed. e) The elevator could be moving downward with decreasing speed.

Front

d

Back

. A ball is whirled on the end of a string in a horizontal circle of radius R at constant speed v. By which one of the following means can the centripetal acceleration of the ball be increased by a factor of two? a) Keep the radius fixed and increase the period by a factor of two. b) Keep the radius fixed and decrease the period by a factor of two. c) Keep the speed fixed and increase the radius by a factor of two. d) Keep the speed fixed and decrease the radius by a factor of two. e) Keep the radius fixed and increase the speed by a factor of two.

Front

d

Back

. If the amount of energy needed to operate a 100 W light bulb for one minute were used to launch a 2-kg projectile, what maximum height could the projectile reach, ignoring any resistive effects? a) 20 m b) 50 m c) 100 m d) 200 m e) 300 m

Front

e

Back

A ball is attached to a string and whirled in a horizontal circle. The ball is moving in uniform circular motion when the string separates from the ball (the knot wasn't very tight). Which one of the following statements best describes the subsequent motion of the ball? a) The ball immediately flies in the direction radially outward from the center of the circular path the ball had been following. b) The ball continues to follow the circular path for a short time, but then it gradually falls away. c) The ball gradually curves away from the circular path it had been following. d) The ball immediately follows a linear path away from, but not tangent to the circular path it had been following. e) The ball immediately follows a line that is tangent to the circular path the ball had been following

Front

e

Back

Consider the recoil of a rifle when it is fired. Recoil is an example of which of the following concepts? a) Newton's Third Law of Motion b) Impulse c) Conservation of Momentum d) all of the above e) none of the above

Front

d

Back

Determine the amount of work done in firing a 2.0-kg projectile with an initial speed of 50 m/s. Neglect any effects due to air resistance. a) 900 J b) 1600 J c) 2500 J d) 4900 J e) This cannot be determined without knowing the launch angle.

Front

c

Back

. An airplane flying at 115 m/s due east makes a gradual turn while maintaining its speed and follows a circular path to fly south. The turn takes 15 seconds to complete. What is the radius of the circular path? a) 410 m b) 830 m c) 1100 m d) 1600 m e) 2200 m

Front

e

Back

A quarter is dropped from rest from the fifth floor of a very tall building. The speed of the quarter is v just before striking the ground. From what floor would the quarter have to be dropped from rest for the speed just before striking the ground to be approximately 2v? Ignore all air resistance effects to determine your answer. a) 14 b) 25 c) 20 d) 7 e) 10

Front

c

Back

. A 28-kg beginning roller skater is standing in front of a wall. By pushing against the wall, she is propelled backward with a velocity of 1.2 m/s. While pushing, her hands are in contact with the wall for 0.80 s. Ignoring frictional effects, find the magnitude and direction of the impulse acting on the skater. a) -34 N s b) +34 N s c) -42 N s d) +42 N s e) -53 N s

Front

a

Back

Kevin is refinishing his rusty wheelbarrow. He moves his sandpaper back and forth 45 times over a rusty area, each time moving a total distance of 0.15 m. Kevin pushes the sandpaper against the surface with a normal force of 1.8 N. The coefficient of friction for the metal/sandpaper interface is 0.92. How much work is done by the kinetic frictional force during the sanding process? a) + 12 J b) - 12 J c) + 24 J d) - 24 J e) zero J

Front

b

Back

. A truck is traveling with a constant speed of 15 m/s. When the truck follows a curve in the road, its centripetal acceleration is 4.0 m/s2. What is the radius of the curve? a) 3.8 m b) 14 m c) 56 m d) 120 m e) 210 m

Front

c

Back

. Consider the following situations: (i) A minivan is following a hairpin turn on a mountain road at a constant speed of twenty miles per hour. (ii) A parachutist is descending at a constant speed 10 m/s. (iii) A heavy crate has been given a quick shove and is now sliding across the floor. (iv) Jenny is swinging back and forth on a swing at the park. (v) A football that was kicked is flying through the goal posts. (vi) A plucked guitar string vibrates at a constant frequency. In which one of these situations does the object or person experience zero acceleration? a) i only b) ii only c) iii and iv only d) iv, v, and vi only e) all of the situations

Front

b

Back

. Determine the amount of work done in firing a 2.0-kg projectile with an initial speed of 50 m/s. Neglect any effects due to air resistance. a) 900 J b) 1600 J c) 2500 J d) 4900 J e) This cannot be determined without knowing the launch angle.

Front

c

Back

Two identical balls are thrown from the same height from the roof of a building. One ball is thrown upward with an initial speed v. The second ball is thrown downward with the same initial speed v. When the balls reach the ground, how do the kinetic energies of the two balls compare? Ignore any air resistance effects. a) The kinetic energies of the two balls will be the same. b) The first ball will have twice the kinetic energy as the second ball. c) The first ball will have one half the kinetic energy as the second ball. d) The first ball will have four times the kinetic energy as the second ball. e) The first ball will have three times the kinetic energy as the second ball.

Front

a

Back

A 1000-kg car travels along a straight portion of highway at a constant velocity of 10 m/s, due east. The car then encounters an unbanked curve of radius 50 m. The car follows the curve traveling at a constant speed of 10 m/s while the direction of the car changes from east to south. What is the magnitude of the frictional force between the tires and the road as the car negotiates the unbanked curve? a) 500 N b) 1000 N c) 2000 N d) 5000 N e) 10 000 N

Front

c

Back

An astronaut drops a golf ball that is initially at rest from a cliff on the surface of the moon. The ball falls freely under the influence of gravity. Which one of the following statements is true concerning the ball as it falls? Neglect any frictional effects. a) The ball will gain an equal amount of kinetic energy during each second. b) The ball will gain an equal amount of momentum during each second. c) The ball will gain an equal amount of momentum during each meter through which it falls. d) The ball will gain twice the amount of speed for each meter through which it falls. e) The amount of momentum the ball gains will be directly proportional to the amount of potential energy that it loses.

Front

b

Back

A 1000-kg car travels along a straight portion of highway at a constant velocity of 10 m/s, due east. The car then encounters an unbanked curve of radius 50 m. The car follows the curve traveling at a constant speed of 10 m/s while the direction of the car changes from east to south. What is the magnitude of the acceleration of the car as it travels the unbanked curve? a) zero m/s2 b) 2 m/s2 c) 5 m/s2 d) 10 m/s2 e) 20 m/s2

Front

b

Back

A donkey pulls a crate up a rough, inclined plane at constant speed. Which one of the following statements concerning this situation is false? a) The gravitational potential energy of the crate is increasing. b) The net work done by all the forces acting on the crate is zero joules. c) The work done on the crate by the normal force of the plane is zero joules. d) The donkey does "positive" work in pulling the crate up the incline. e) The work done on the object by gravity is zero joules.

Front

e

Back

A sled of mass m is coasting at a constant velocity on the ice covered surface of a lake. Four birds, with a combined mass 0.5m, gently land at the same time on the sled. The sled and birds continue sliding along the original direction of motion. How does the kinetic energy of the sled and birds compare with the initial kinetic energy of the sled before the birds landed? a) The final kinetic energy is one half of the initial kinetic energy. b) The final kinetic energy is one third of the initial kinetic energy. c) The final kinetic energy is one quarter of the initial kinetic energy. d) The final kinetic energy is one ninth of the initial kinetic energy. e) The final kinetic energy is equal to the initial kinetic energy.

Front

b

Back

. A steel ball is whirled on the end of a chain in a horizontal circle of radius R with a constant period T. If the radius of the circle is then reduced to 0.75R, while the period remains T, what happens to the centripetal acceleration of the ball? a) The centripetal acceleration increases to 1.33 times its initial value. b) The centripetal acceleration increases to 1.78 times its initial value. c) The centripetal acceleration decreases to 0.75 times its initial value. d) The centripetal acceleration decreases to 0.56 times its initial value. e) The centripetal acceleration does not change.

Front

c

Back

. A water balloon is dropped from a third story balcony. The balloon bursts when it hits the ground. It is a completely inelastic collision with the earth. How much kinetic energy is transferred to the earth as a result of the collision? a) mv2/2 b) mv2 c) mv d) 2mv2 e) zero joules

Front

e

Back

A mountain climber pulls a supply pack up the side of a mountain at constant speed. Which one of the following statements concerning this situation is false? a) The net work done by all the forces acting on the pack is zero joules. b) The work done on the pack by the normal force of the mountain is zero joules. c) The work done on the pack by gravity is zero joules. d) The gravitational potential energy of the pack is increasing. e) The climber does "positive" work in pulling the pack up the mountain.

Front

c

Back

A girl is swinging on a swing in the park. As she wings back and forth, she follows a path that is part of a vertical circle. Her speed is maximum at the lowest point on the circle and temporarily zero m/s at the two highest points of the motion as her direction changes. Which of the following forces act on the girl when she is at the lowest point on the circle? a) the force of gravity, which is directed downward b) the force which is directed radially outward from the center of the circle c) the tension in the chains of the swing, which is directed upward d) answers b and c only e) answers a and c only

Front

e

Back

. A small asteroid collides with a planet. Which one of the following statements concerning what happens during the collision is correct? a) The asteroid exerts a smaller force on the planet than the planet exerts on the asteroid. b) The planet exerts a force on the asteroid, but the asteroid does not exert a force on the planet. c) The asteroid exerts the same amount of force on the planet as the planet exerts on the asteroid. d) The asteroid exerts a force on the planet, but the planet does not exert a force on the asteroid. e) The planet exerts a smaller force on the asteroid than the asteroid exerts on the planet.

Front

c

Back

. A boy is whirling a stone at the end of a string around his head. The string makes one complete revolution every second, and the tension in the string is FT. The boy increases the speed of the stone, keeping the radius of the circle unchanged, so that the string makes two complete revolutions per second. What happens to the tension in the sting? a) The tension increases to four times its original value. b) The tension increases to twice its original value. c) The tension is unchanged. d) The tension is reduced to one half of its original value. e) The tension is reduced to one fourth of its original value.

Front

a

Back

Three events are observed at a baseball game: I. A baseball is thrown by a pitcher. It starts from rest and is traveling at +38 m/s as it flies toward the catcher. II. A baseball is traveling at +38 m/s when it enters the catcher's glove and stops. III. A baseball is traveling at +38 m/s when it hits a wall and bounces away from the wall at 38 m/s. The change in the momentum of the baseball has the largest magnitude in which case(s)? a) I only b) II only c) III only d) I and II only e) II and III only

Front

c

Back

During the filming of a movie, a stunt person jumps from the roof of a tall building, but no injury occurs because the person lands on a large, air-filled bag. Which one of the following best describes why no injury occurs? a) The bag increases the amount of time the force acts on the person and reduces the change in momentum. b) The bag increases the amount of time during which the momentum is changing and reduces the average force on the person. c) The bag decreases the amount of time during which the momentum is changing and reduces the average force on the person. d) The bag provides the necessary force to stop the person. e) The bag reduces the impulse to the person.

Front

b

Back

. Some children are practicing catching baseballs. The coach tosses the ball into the air and hits the ball with his bat. The ball travels nearly horizontally, directly at the short stop who manages to catch the line drive. Did the coach, via the bat, do any work on the ball as it was hit? a) No, it travels nearly horizontally, and no work is done. b) Yes, work was done on the ball because during the time the force acted on the ball, the bat and ball moved through some distance. c) No, there was a force acting on the ball, but there was no displacement while the force was acting. d) Yes, work was done on the ball because the force of gravity was acting on the ball while it was being hit. e) No work was done on the ball because the ball flew even though the force was no longer acting on it.

Front

b

Back

You are riding in the forward passenger seat of a car as it travels along a straight portion of highway. The car continues traveling at a constant speed as it follows a sharp, unbanked curve to the left. You feel the door pushing on the right side of your body. Which of the following forces in the horizontal direction are acting on you? a) a static frictional force between you and the seat b) a normal force of the door c) a force pushing you toward the door d) answers a and b e) answers a and c

Front

d

Back

A rancher puts a hay bail into the back of her SUV. Later, she drives around an unbanked curve with a radius of 48 m at a speed of 16 m/s. What is the minimum coefficient of static friction for the hay bail on the floor of the SUV so that the hay bail does not slide while on the curve? a) This cannot be determined without knowing the mass of the hay bail. b) 0.17 c) 0.33 d) 0.42 e) 0.54

Front

e

Back

Two balls of equal size are dropped from the same height from the roof of a building. One ball has twice the mass of the other. When the balls reach the ground, how do the kinetic energies of the two balls compare? a) The lighter one has one fourth as much kinetic energy as the other does. b) The lighter one has one half as much kinetic energy as the other does. c) The lighter one has the same kinetic energy as the other does. d) The lighter one has twice as much kinetic energy as the other does. e) The lighter one has four times as much kinetic energy as the other does.

Front

b

Back

. Object A is traveling due north while object B is traveling due south along the same line. The two objects have a head-on collision. Which one of the following statements best describes the velocities of the objects after the collision? a) The final velocity of B will be the same as the initial velocity of A and vice versa. b) The final velocities of both A and B will be less than the velocities before collision c) The final velocities of A and B will be the same as they had before the collision. d) The final velocities of A and B could be equal to zero m/s. e) The final velocities of A and B will be equal to zero m/s.

Front

d

Back

At a circus, a clown on a motorcycle with a mass M travels along a horizontal track and enters a vertical circle of radius r. Which one of the following expressions determines the minimum speed that the motorcycle must have at the top of the track to remain in contact with the track? a) b) c) v = gR d) v = 2gR e) v = MgR

Front

b

Back

An aluminum rod is designed to break when it is under a tension of 600 N. One end of the rod is connected to a motor and a 12-kg spherical object is attached to the other end. When the motor is turned on, the object moves in a horizontal circle with a radius of 6.0 m. If the speed of the motor is continuously increased, at what speed will the rod break? Ignore the mass of the rod for this calculation. a) 11 m/s b) 17 m/s c) 34 m/s d) 88 m/s e) 3.0 × 102 m/s

Front

b

Back

Which one of the following choices represents the largest kinetic energy? a) Mars is moving in its orbit around the Sun. b) A cyclist is racing in the annual Tour de France bicycle race. c) A leaf falls from a tree. d) A cheetah runs at its maximum speed to catch a fleeing zebra. e) An oil tanker sails through the Panama Canal.

Front

a

Back

. You are investigating the safety of a playground slide. You are interested in finding out what the maximum speed will be of children sliding on it when the conditions make it very slippery (assume frictionless). The height of the slide is 2.5 m. What is that maximum speed of a child if she starts from rest at the top? a) 1.9 m/s b) 2.5 m/s c) 4.9 m/s d) 7.0 m/s e) 9.8 m/s

Front

d

Back

. A rubber ball is dropped from rest from a height h. The ball bounces off the floor and reaches a height of 2h/3. How can we use the principle of the conservation of mechanical energy to interpret this observation? a) During the collision with the floor, the floor did not push hard enough on the ball for it to reach its original height. b) Some of the ball's potential energy was lost in accelerating it toward the floor. c) The force of the earth's gravity on the ball prevented it from returning to its original height. d) Work was done on the ball by the gravitational force that reduced the ball's kinetic energy. e) Work was done on the ball by non-conservative forces that resulted in the ball having less total mechanical energy after the bounce.

Front

e

Back

. A 9-kg object is at rest. Suddenly, it explodes and breaks into two pieces. The mass of one piece is 6 kg and the other is a 3-kg piece. Which one of the following statements concerning these two pieces is correct? a) The speed of the 6-kg piece will be one eighth that of the 3-kg piece. b) The speed of the 3-kg piece will be one fourth that of the 6-kg piece. c) The speed of the 6-kg piece will be one forth that of the 3-kg piece. d) The speed of the 3-kg piece will be one half that of the 6-kg piece. e) The speed of the 6-kg piece will be one half that of the 3-kg piece.

Front

e

Back

A roller coaster car travels down a hill and is moving at 18 m/s as it passes through a section of straight, horizontal track. The car then travels up another hill that has a maximum height of 15 m. If frictional effects are ignored, determine whether the car can reach the top of the hill. If it does reach the top, what is the speed of the car at the top? a) No, the car doesn't make it up the hill. It is going too slow. b) Yes, the car just barely makes it to the top and stops. The final speed is zero m/s. c) Yes, the car not only makes it to the top, but it is moving at 5.4 m/s. d) Yes, the car not only makes it to the top, but it is moving at 9.0 m/s. e) Yes, the car not only makes it to the top, but it is moving at 18 m/s.

Front

c

Back

Complete the following statement: The maximum speed at which a car can safely negotiate an unbanked curve depends on all of the following factors except a) the coefficient of kinetic friction between the road and the tires. b) the coefficient of static friction between the road and the tires. c) the acceleration due to gravity. d) the diameter of the curve. e) the ratio of the static frictional force between the road and the tires and the normal force exerted on the car.

Front

a

Back

Section 4

(50 cards)

Object A is attached to ideal spring A and is moving in simple harmonic motion. Object B is attached to ideal spring B and is moving in simple harmonic motion. The period and the amplitude of object B are both two times the corresponding values for object A. How do the maximum speeds of the two objects compare? a) The maximum speed of A is one fourth that of object B. b) The maximum speed of A is one half that of object B. c) The maximum speed of A is the same as that of object B. d) The maximum speed of A is two times that of object B. e) The maximum speed of A is four times that of object B.

Front

c

Back

. A block is attached to the end of a horizontal ideal spring and rests on a frictionless surface. The other end of the spring is attached to a wall. The block is pulled away from the spring's unstrained position by a distance x0 and given an initial speed of v0 as it is released. Which one of the following parameters must be known in addition to x0 and v0 to determine the amplitude of the subsequent simple harmonic motion? a) period b) spring constant c) mass of the block d) the direction of the initial velocity of the block e) the direction of the initial displacement of the block

Front

a

Back

A spring is hung vertically from a fixed support. When an object of mass m is attached to the end of the spring, it stretches by a distance y. When an object of mass of 2m is hung from the spring, it stretches by a distance 2y. A second, identical spring is then attached to the free end of the first spring. If the object of mass 2m is attached to the bottom of the second spring, how far will the bottom of the second spring move downward from its unstretched position? Assume the masses of the springs are negligible when compared to m. a) y/2 b) y c) 3y/2 d) 2y e) 4y

Front

e

Back

An airplane starts from rest at the end of a runway and begins accelerating. The tires of the plane are rotating with an angular velocity that is uniformly increasing with time. On one of the tires, Point A is located on the part of the tire in contact with the runway surface and point B is located halfway between Point A and the axis of rotation. Which one of the following statements is true concerning this situation? a) Both points have the same tangential acceleration. b) Both points have the same centripetal acceleration. c) Both points have the same instantaneous angular velocity. d) The angular velocity at point A is greater than that of point B. e) Each second, point A turns through a greater angle than point B.

Front

c

Back

. At the circus, a clown balances a step ladder on his forehead. A few people in the audience notice that he is continually moving to keep the ladder from falling off his forehead. Why is this movement necessary? The clown is trying to apply a torque to the ladder in the direction opposite to other torques on the ladder. b) The clown is trying to keep the center of mass of the ladder directly above his head so that the torque due to the gravitational force is zero Nm. c) By rocking the ladder on his forehead, the ladder will be more stable than if it were stationary. This is similar to riding a bicycle. You can easily balance a bicycle when it's rolling, but not when it's stationary. d) This movement is not necessary. The clown is trying to make this look harder than it really is for entertainment value. The ladder will easily balance on the clown's forehead.

Front

c

Back

You would like to use a simple pendulum to determine the local value of the acceleration due to gravity, g. Consider the following parameters: (1) pendulum length, (2) mass of the object at the free end of the pendulum, (3) the period of the pendulum as it swings in simple harmonic motion, (4) the amplitude of the motion. Which of these parameters must be measured to find a value for g? a) 1 only b) 2 only c) 3 and 4 only d) 1 and 3 only e) 1, 2, and 4 only

Front

d

Back

A wheel starts from rest and rotates with a constant angular acceleration. What is the ratio of the instantaneous tangential acceleration at point A located a distance 2r to that at point B located at r, where the radius of the wheel is R = 2r? a) 0.25 b) 0.50 c) 1.0 d) 2.0 e) 4.0

Front

d

Back

. Block A has a mass m and block B has a mass 2m. Block A is pressed against a spring to compress the spring by a distance x. It is then released such that the block eventually separates from the spring and it slides across a surface where the friction coefficient is µk. The same process is applied to block B. Which one of the following statements concerning the distance that each block slides before stopping is correct? a) Block A slides one-fourth the distance that block B slides. b) Block A slides one-half the distance that block B slides. c) Block A slides the same distance that block B slides. d) Block A slides twice the distance that block B slides. e) Block A slides four times the distance that block B slides

Front

d

Back

A solid sphere of radius R rotates about an axis that is tangent to the sphere with an angular speed w. Under the action of internal forces, the radius of the sphere increases to 2R. What is the final angular speed of the sphere? a) w/4 b) w/2 c) w d) 2w e) 4w

Front

a

Back

When using pruning shears, such as the pair shown, to cut a branch from a tree, it is better to insert the branch closer to the hinge than near the end of the shears. Which one of the following statements best explains the reason this observation is true? a) The torque acting on the branch is smallest near the hinge. b) The torque acting on the branch is largest near the hinge. c) The torque exerted on the shears yields the greatest force on the branch near the hinge. d) The long handles determine the force exerted on the branch, which is the same no matter where on the shears the branch is placed. e) The same torque is exerted on the shears and the branch, regardless of the force applied to the handles.

Front

c

Back

. In a classroom demonstration, a physics professor breathes in a small amount of helium and begins to talk. The result is that the professor's normally low, baritone voice sounds quite high pitched. Which one of the following statements best describes this phenomena? a) The presence of helium changes the speed of sound in the air in the room, causing all sounds to have higher frequencies. b) The professor played a trick on the class by tightening his vocal cords to produces higher frequencies in his throat and mouth than normal. The helium was only a distraction and had nothing to do with it. c) The helium significantly alters the vocal chords causing the wavelength of the sounds generated to decrease and thus the frequencies increase. d) The wavelength of the sound generated in the professor's throat and mouth is only changed slightly, but since the speed of sound in helium is approximately 2.5 times larger than in air, therefore the frequencies generated are about 2.5 times higher.

Front

d

Back

A ball is thrown downward; and its speed is v just before it strikes the ground. After the collision with the earth, it heads upward with a speed v. Which one of the following statements concerning this situation is true? a) Only the momentum of the earth is changed by the collision. b) The momentum of the earth is not changed by the collision. c) Only the momentum of the ball is changed by the collision. d) The momentum of the ball is not changed by the collision. e) The collision causes both the momentum and the kinetic energy of the ball to change.

Front

a

Back

Which one of the following statements concerning a wheel undergoing rolling motion is true? a) The angular acceleration of the wheel must be zero m/s2. b) The tangential velocity is the same for all points on the wheel. c) The linear velocity for all points on the rim of the wheel is non-zero. d) The tangential velocity is the same for all points on the rim of the wheel. e) There is no slipping at the point where the wheel touches the surface on which it is rolling.

Front

e

Back

. Complete the following statement: For a wheel that turns with constant angular speed, a) each point on its rim moves with constant acceleration. b) the wheel turns through "equal angles in equal times." c) each point on the rim moves at a constant velocity. d) the angular displacement of a point on the rim is constant. e) all points on the wheel are moving at a constant velocity.

Front

b

Back

Over the course of a day (twenty-four hours), what is the angular displacement of the second hand of a wrist watch in radians? a) 1440 rad b) 2880 rad c) 4520 rad d) 9050 rad e) 543 000 rad

Front

d

Back

Joe has volunteered to help out in his physics class by sitting on a stool that easily rotates. Joe holds the dumbbells out as shown as the stool rotates. Then, Joe drops both dumbbells. Then, the angular momentum of Joe and the stool changes, but the angular velocity does not change. Which of the following choice offers the best explanation? a) The force exerted by the dumbbells acts in opposite direction to the torque. b) Angular momentum is conserved, when no external forces are acting. c) Even though the angular momentum decreases, the moment of inertia also decreases. d) The decrease in the angular momentum is balanced by an increase in the moment of inertia. e) The angular velocity must increase when the dumbbells are dropped.

Front

c

Back

On an air hockey table, two identical pucks have an elastic collision. Puck A is observed to be traveling northeast at v m/s before the collision and northwest at v m/s after the collision. Puck B is observed to be traveling northwest at v m/s before the collision and northeast at v m/s after the collision. Describe the direction of the impulse exerted on each disk during the collision. a) The impulse on puck A is directed due west and the impulse on puck B is directed due east. b) The impulse on puck A is directed due east and the impulse on puck B is directed due west. c) The impulse on puck A is directed due north and the impulse on puck B is directed due north. d) The impulse on puck A is directed northwest and the impulse on puck B is directed northeast. e) The impulse on puck A is directed southwest and the impulse on puck B is directed southeast.

Front

a

Back

Joe has volunteered to help out in his physics class by sitting on a stool that easily rotates. Joe holds the dumbbells out as shown as the stool rotates. Then, Joe drops both dumbbells. How does the rotational speed of stool change, if at all? a) The rotational speed increases. b) The rotational speed decreases, but Joe continues to rotate. c) The rotational speed remains the same. d) The rotational speed quickly decreases to zero rad/s.

Front

c

Back

. A star is rotating about an axis that passes through its center. When the star "dies," the balance between the inward pressure due to the force of gravity and the outward pressure from nuclear processes is no longer present and the star collapses inward; and its radius decreases with time. Which one of the following choices best describes what happens as the star collapses? a) The angular velocity of the star remains constant. b) The angular momentum of the star remains constant. c) The angular velocity of the star decreases. d) The angular momentum of the star decreases. e) Both angular momentum and angular velocity increase.

Front

b

Back

Two identical cars were involved in a collision at an icy intersection. Car A was stopped at a traffic light. Car B was moving at a speed v when it suffered a perfectly inelastic collision with the back end of car A. With what speed did the two cars slide into the intersection after the collision? a) 2v b) v c) v/2 d) v/4 e) v/8

Front

c

Back

. A circular hoop rolls without slipping on a flat horizontal surface. Which one of the following is necessarily true? a) All points on the rim of the hoop have the same speed. b) All points on the rim of the hoop have the same velocity. c) Every point on the rim of the wheel has a different velocity. d) All points on the rim of the hoop have acceleration vectors that are tangent to the hoop. e) All points on the rim of the hoop have acceleration vectors that point toward the center of the hoop.

Front

c

Back

Two solid disks, which are free to rotate independently about the same axis that passes through their centers and perpendicular to their faces, are initially at rest. The two disks have the same mass, but one of has a radius R and the other has a radius 2R. A force of magnitude F is applied to the edge of the larger radius disk and it begins rotating. What force must be applied to the edge of the smaller disk so that the angular acceleration is the same as that for the larger disk? Express your answer in terms of the force F applied to the larger disk. a) 0.25F b) 0.50F c) F d) 1.5F e) 2F

Front

b

Back

. Joe has volunteered to help out in his physics class by sitting on a stool that easily rotates. As Joe holds the dumbbells out as shown, the professor temporarily applies a sufficient torque that causes him to rotate slowly. Then, Joe brings the dumbbells close to his body and he rotates faster. Why does his speed increase? a) By bringing the dumbbells inward, Joe exerts a torque on the stool. b) By bringing the dumbbells inward, Joe decreases the moment of inertia. c) By bringing the dumbbells inward, Joe increases the angular momentum. d) By bringing the dumbbells inward, Joe increases the moment of inertia. e) By bringing the dumbbells inward, Joe decreases the angular momentum

Front

b

Back

Two girl scouts are sitting in a large canoe on a still lake while at summer camp. The canoe happens to be oriented with the front of the canoe pointing due north. One of the girls is at the front of the canoe and the other is at the back of the canoe. The girl at the front walks to sit next to her friend at the back and sits down. What effect does this event have on the canoe? a) The canoe will still be at rest, but it will be south of its original position. b) The canoe will still be at rest, but it will be north of its original position. c) The canoe will be moving toward the south. d) The canoe will be moving toward the north. e) The canoe will still be at rest at its original position

Front

a

Back

For many centuries, soldiers have been trained to march side by side with their steps matching all of the other soldiers. At time t = 0 s, the soldiers all step with their left feet and continue marching with the same period. When they come upon a bridge, how should they change their marching, if at all? a) They should continue marching with the same period. b) Every other row of soldiers should take two steps for every one taken by the rows of soldiers ahead and behind them. c) Every other row of soldiers should take a step with their right foot when the rows of soldiers ahead and behind them are stepping with their left feet, but keep marching with the same period. d) They should all walk at their own pace so that they do not cause resonance on the bridge.

Front

d

Back

Consider the Earth and Mars in their orbit around the Sun. Where is the center of mass located for this three body system? a) It is closer to the Earth, than it is to either the Sun or Mars. b) It is at the center of a triangle that has the Sun at one apex, the Earth at another apex, and Mars at the third apex. c) It is half of the distance between the Sun and Mars. d) It is closer to the Sun, than it is to either the Earth or Mars. e) It is closer to Mars, than it is to either the Earth or the Sun.

Front

d

Back

A climbing rope is hanging from the ceiling in a gymnasium. A student grabs the end of the rope and begins moving it back and forth with a constant amplitude and frequency. A transverse wave moves up the rope. Which of the following statements describing the speed of the wave is true? a) The speed of the wave decreases as it moves upward. b) The speed of the wave increases as it moves upward. c) The speed of the wave is constant as it moves upward. d) The speed of the wave does not depend on the mass of the rope. e) The speed of the wave depends on its amplitude.

Front

b

Back

A girl is sitting on the edge of a merry-go-round at a playground as shown. Looking down from above, the merry-go-round is rotating clockwise. What is the direction of the girl's angular velocity? a) upward b) downward c) left d) right e) There is no direction since it is the merry go round that has the angular velocity.

Front

b

Back

While setting up a simple pendulum, Jon hangs a ball on one end of a steel wire of diameter d and attaches the other end to the ceiling. While the ball is stationary, Jon measures the length of the wire and finds that the length has increased by a distance y. Which one of the following options should Jon follow to minimize the amount the length changes? a) Cut the wire in half and use one half to hang the ball from the ceiling. b) Replace the wire with one of identical dimensions, but composed of tungsten. c) Replace the ball with one with one half the mass of the original ball. d) Connect the pendulum to a fixture that allows the pendulum to swing closer to the ground. e) Replace the wire with one made of the same material and of the same length, but with a diameter 2d.

Front

e

Back

. An interesting method for exercising a dog is to have it walk on the rough surface of a circular platform that freely rotates about its center as shown. When the dog begins walking near the outer edge of the platform as shown, how will the platform move, if at all? Assume the bearing on which the platform can rotate is frictionless. a) When the dog walks, the platform will rotate counterclockwise when viewed from above. b) When the dog walks, the platform will rotate clockwise when viewed from above. c) When the dog walks, the platform will not rotate.

Front

a

Back

A pair of fuzzy dice is hanging from the rearview mirror of a sports car. As the car accelerates smoothly, the strings of the dice are tilted slightly toward the rear of the car. From the perspective of the driver, which one of the following statements is true, if the dice are stationary? a) The dice are in static equilibrium. b) The dice are not in equilibrium because the torque on the dice is not zero. c) The dice are in equilibrium, but not static equilibrium. d) The dice are not in equilibrium because the linear momentum of the dice is not zero. e) None of the above statements are true.

Front

b

Back

While constructing a rail line in the 1800s, spikes were driven to attach the rails to cross ties with a sledge hammer. Consider the sound that is generated each time the hammer hits the spike. How does the frequency of the sound change, if at al, as the spike is driven into the tie? a) The frequency of the sound does not change as the spike is driven. b) The frequency of the sound decreases as the spike is driven. c) The frequency of the sound increases as the spike is driven.

Front

c

Back

Jimmy and Jenny are floating on a quiet river using giant doughnut-shaped tubes. At one point, they are 5.0 m apart when a speed boat passes. After the boat passes, they begin bobbing up and down at a frequency of 0.25 Hz. Just as Jenny reaches her highest level, Jimmy is at his lowest level. As it happens, Jenny and Jimmy are always within one wavelength. What is the speed of these waves? a) 1.3 m/s b) 2.5 m/s c) 3.8 m/s d) 5.0 m/s e) 7.5 m/s

Front

b

Back

Mike is holding one end of a Slinky. His hand moves up and down and causes a transverse wave to travel along the Slinky away from him. Is the motion of Mike's hand a wave? a) Yes, the motion of Mike's hand is a wave because it moves up and down in periodic motion. b) Yes, the motion of Mike's hand is a wave because Mike is transferring energy to the Slinky. c) No, the motion of Mike's hand is not a wave because there is no traveling disturbance. d) No, the motion of Mike's hand is not a wave because there is no energy traveling along the Slinky.

Front

c

Back

A packaged roll of paper towels falls from a shelf in a grocery store and rolls due south without slipping. As its linear speed slows, what are the directions of the paper towels' angular velocity and angular acceleration? a) east, east b) west, east c) south, north d) east, west e) west, west

Front

d

Back

A 2.00-kg block is attached to the end of a horizontal ideal spring and rests on a frictionless surface. The other end of the spring is attached to a wall. After being displaced a small distance and released from rest, the block is observed to oscillate at a frequency of 2.77 Hz. The spring is then cut in half. One of the halves is then connected between the wall and the block. What will be the frequency when the block is displaced and released from rest again? a) 5.54 Hz b) 3.91 Hz c) 2.77 Hz d) 1.96 Hz e) 1.39 Hz

Front

b

Back

. A longitudinal wave with an amplitude of 0.02 m moves horizontally along a Slinky with a speed of 2 m/s. Which one of the following statements concerning this wave is true? a) Each particle in the Slinky moves a distance of 2 m each second. b) Each particle in the Slinky moves a vertical distance of 0.04 m during each period of the wave. c) Each particle in the Slinky moves a horizontal distance of 0.04 m during each period of the wave. d) Each particle in the Slinky moves a vertical distance of 0.02 m during each period of the wave. e) Each particle in the Slinky has a wavelength of 0.04 m.

Front

c

Back

. A block is attached to the end of a horizontal ideal spring and rests on a rough surface. The other end of the spring is attached to a wall. The block is pulled away from the spring's unstrained position and released from rest. The block begins oscillating, but the amplitude is observed to decrease with time. After a relatively short time, the block stops oscillating. For which of the following conditions, would the harmonic motion of this system be described as underdamped? a) The frictional force is greater than the elastic force. b) The frictional force is less than the elastic force. c) The work done by the frictional force is greater than the elastic potential energy. d) The kinetic energy of the block is greater than the elastic potential energy. e) This kind of system would not show damped harmonic motion.

Front

b

Back

The propeller of an airplane is at rest when the pilot starts the engine; and its angular acceleration is a constant value. Two seconds later, the propeller is rotating at 10pi rad/s. Through how many revolutions has the propeller rotated through during the first two seconds? a) 300 b) 50 c) 20 d) 10 e) 5

Front

e

Back

Two rods are made out of brass and have the same length. The cross section of one of the rods is circular with a diameter 2a. The other rod has a square cross section, where each side of the square is a length 2a. One end of the rods is attached to an immovable fixture which allows the rods to hang vertically. To the free end of each rod, a block of mass m is attached. Which rod, if either, will stretch more after the block is attached? a) The one with the circular cross section will stretch more. b) The one with the square cross section will stretch more. c) Both will stretch by the same amount. d) One cannot say which will stretch more without knowing the numerical values of a and m.

Front

a

Back

. A bell is ringing inside of a sealed glass jar that is connected to a vacuum pump. Initially, the jar is filled with air at atmospheric pressure. What does one hear as the air is slowly removed from the jar by the pump? a) The sound intensity gradually increases. b) The sound intensity gradually decreases. c) The sound intensity of the bell does not change. d) The frequency of the sound gradually increases. e) The frequency of the sound gradually decreases.

Front

b

Back

A packaged roll of paper towels falls from a shelf in a grocery store and rolls due south without slipping. What is the direction of the paper towels' angular velocity? a) north b) east c) south d) west e) down

Front

b

Back

In designing a spring loaded cannon, determine the spring constant required to launch a 2.0-kg ball with an initial speed of 1.2 m/s from a position where the spring is displaced 0.15 m from its equilibrium position. a) 16 N/m b) 32 N/m c) 64 N/m d) 130 N/m e) 180 N/m

Front

c

Back

A 1.5-kg ball is tied to the end of a string. The ball is then swung at a constant angular velocity of 4pi rad/s in a horizontal circle of radius 2.0 m. What is the torque on the stone? a) 18 Nm b) 29 Nm c) 36 Nm d) 59 Nm e) zero Nm

Front

e

Back

. A 4.0-m board is resting directly on top of a 4.0-m long table. The weight of the board is 340 N. An object with a weight of 170 N is placed at the right end of the board. What is the maximum horizontal distance that the board can be moved toward the right such that the board remains in equilibrium? a) 0.75 m b) 1.0 m c) 1.3 m d) 1.5 m e) 2.0 m

Front

c

Back

The tension of a guitar string in increased by a factor of 4. How does the speed of a wave on the string increase, if at all? a) The speed of a wave is reduced to one-fourth the value it had before the increase in tension. b) The speed of a wave is reduced to one-half the value it had before the increase in tension. c) The speed of a wave remains the same as before the increase in tension. d) The speed of a wave is increased to two times the value it had before the increase in tension. e) The speed of a wave is increased to four times the value it had before the increase in tension.

Front

d

Back

Natalie is a distance d in front of a speaker emitting sound waves. She then moves to a position that is a distance 2d in front of the speaker. By what percentage does the sound intensity decrease for Natalie between the two positions? a) 10 % b) 25 % c) 50 % d) 75% e) The sound intensity remains constant because it is not dependent on the distance.

Front

d

Back

. Children sometimes play with water rockets, in which an inner compartment is partially filled with water. The air pocket above the water is pressurized using a small pump. When the rocket is released from the pump, it flies upward at an initial velocity of 17 m/s as water exits through a nozzle at the bottom that has a radius of 2.5 mm. If the density of the water is 999 kg/m3, what is the initial thrust of the rocket? a) 0.33 N b) 5.7 N c) 0.88 N d) 2.4 N e) 3.7 N

Front

b

Back

An ideal spring is hung vertically from a fixed support. When an object of mass m is attached to the end of the spring, it stretches by a distance y. The object is then lifted and held to a height y +A, where A << y. Which one of the following statements concerning the total potential energy of the object is true? a) The total potential energy will be equal to zero joules. b) The total potential energy will decrease and be equal to the gravitational potential energy of the object. c) The total potential energy will decrease and be equal to the elastic potential energy of the spring. d) The total potential energy will decrease and be equal to the sum of elastic potential energy of the spring and the gravitational potential energy of the object. e) The total potential energy will increase and be equal to the sum of elastic potential energy of the spring and the gravitational potential energy of the object.

Front

e

Back

. The Earth, which has an equatorial radius of 6380 km, makes one revolution on its axis every 23.93 hours. What is the tangential speed of Nairobi, Kenya, a city near the equator? a) 37.0 m/s b) 74.0 m/s c) 148 m/s d) 232 m/s e) 465 m/s

Front

e

Back

Section 5

(3 cards)

A sound level meter is used measure the sound intensity level. A sound level meter is placed an equal distance in front of two speakers, one to the left and one to the right. A signal of constant frequency, but differing amplitude, is sent to each speaker independently. When the left speaker is turned on the sound level meter reads 85 dB. When the right speaker is turned on the sound level meter reads 65 dB. What will the sound level meter read when both speakers are turned on at the same time? a) about 85 dB b) about 65 dB c) about 150 dB d) about 75 dB e) about 113 dB

Front

a

Back

Software is used to amplify a digital sound file on a computer by 20 dB. By what factor has the intensity of the sound been increased as compared to the original sound file? a) 2 b) 5 c) 10 d) 20 e) 100

Front

e

Back

Hydrogen atoms in a distant galaxy are observed to emit light that is shifted to lower frequencies with respect to hydrogen atoms here on Earth. Astronomers use this information to determine the relative velocity of the galaxy with respect to the Earth by observing how light emitted by atoms is Doppler shifted. For the hydrogen atoms mentioned, how are the wavelengths of light affected by the relative motion, if at all? a) The wavelengths would be unchanged, only the frequencies are shifted. b) The wavelengths of light would be longer than those observed on Earth. c) The wavelengths of light would be shorter than those observed on Earth.

Front

b

Back