Section 1
Preview this deck
The figure shows the velocity versus time graph for a car driving on a straight road. Which of the following best describes the acceleration of the car?
Front
| 5 | 0 | ||
| 4 | 0 | ||
| 3 | 0 | ||
| 2 | 0 | ||
| 1 | 0 |
Active users
0
All-time users
0
Favorites
0
Last updated
6 years ago
Date created
Mar 1, 2020
Cards (70)
Section 1
(50 cards)
The figure shows the velocity versus time graph for a car driving on a straight road. Which of the following best describes the acceleration of the car?
The acceleration of the car is positive and decreasing
A plastic ball in a liquid is acted upon by its weight and by a buoyant force. The weight of the ball is 6.7 N. The buoyant force has a magnitude of 9.4 N and acts vertically upward. At a given instant, the ball is released from rest. The acceleration of the ball at that instant, including direction, is closest to
first find the mass of the ball. (6.7/9.8) that mass times the acceleration (m *x)= Fb iddkkk answer: 3.9 m/s2 upward
the following statements are true.
The total mechanical energy of a system is constant only if conservative forces act. Mechanical energy can be dissipated to nonmechanical forms of energy.
For general projectile motion, which of the following best describes the vertical component of a projectile's acceleration? Assume air resistance is negligible
The vertical component of a projectile's acceleration remains a nonzero constant.
Consider a physical situation in which a particle moves from point A to point B. This process is described from two coordinate systems that are identical except that they have different origins. The __________ of the particle at point A differ(s) as expressed in one coordinate system compared to the other, but the __________ from A to B is/are the same as expressed in both coordinate systems.
position, displacement
For a projectile launched horizontally, which of the following best describes the horizontal component of a projectile's velocity? Assume air resistance is negligible
The horizontal component of the projectile's velocity remains a nonzero constant
true statements
The SI unit of power is the watt. Power is the rate at which energy is transformed. Power is the rate at which work is done. A person is limited in the total work he or she can do by the rate at which energy can be transformed.
A packing crate is sitting at rest on an inclined loading ramp. How does the magnitude of the force of static friction compare to the other forces acting on the crate?
The magnitude of the force of static friction is equal to the magnitude of the component of the weight of the crate parallel to the inclined ramp.
For general projectile motion, which of the following best describes the horizontal component of a projectile's acceleration? Assume air resistance is negligible
The horizontal component of a projectile's acceleration is zero
Two objects are moving at equal speed along a level, frictionless surface. The second object has twice the mass of the first object. They both slide up the same frictionless incline plane. Which object rises to a greater height?
The two objects rise to the same height. the formula in use is square root of 2gh
An object is moving with constant velocity. Which of the following best describes the force(s) acting on the object?
No forces are acting on the object.
An airplane needs to reach a velocity of 186 km/h to take off. On a 2000 m runway, what is the minimum acceleration necessary for the plane to take flight?
0.67 m/s2
A large truck collides head-on with a small car. The car is severely damaged as a result of the collision. According to Newton's third law, how do the forces acting between the truck and car compare during the collision?
The force on the truck is equal to the force on the car.
A crate slides up an inclined ramp and then slides down the ramp after momentarily stopping near the top. This crate is acted upon by friction on the ramp and accelerates both ways
The acceleration going up the ramp is greater than the acceleration going down
At what angle, above the horizon, should a cannon be fired in order for the cannon ball to obtain the greatest horizontal range? Assume air resistance is negligible
The cannon should be fired at an angle of 45° above the horizon
An object of weight W falls from rest subject to a frictional drag force bv2. What maximum ("terminal") velocity will it approach if W = 4 N and b = 3 N⋅s2/m?
v = 1.15 m/s Terminal velocity: net forces = 0 therefore the weight is equal to drag force solve for v.
If the net work done on an object is positive, what can you conclude about the object's motion?
The object is speeding up the positive work done increases the energy of the body, since work is equal to F . r thus f and r must be in the same direction, thus increasing the velocity of the body
An elevator moves straight upward at a constant speed. Newton's first law predicts that the net force acting on the elevator will _____.
be zero
Which of the following best describes how to calculate the average acceleration of any object?
Average acceleration is always equal to the change in velocity of an object divided by the time interval
A pool ball is rolling along a table with a constant velocity. The components of its velocity vector are vx=0.6m/s and vy=0.8m/s. Calculate the distance it travels in 0.3 s
0.30 m
A vector has, by definition, both __________ and direction.
magnitude
Speed differs from velocity in the same way that __________ differs from displacement
distance
An object is at rest on a tabletop. Earth pulls downward on this object with a force equal in magnitude to mg. If this force serves as the action force, what is the reaction force in the action-reaction pair?
the object pulling upward on Earth
A ball is thrown straight upward. How does the sign of the work done by gravity while the ball is traveling upward compare with the sign of the work done by gravity while the ball is traveling downward?
Work done by gravity is negative while the ball is traveling upward and positive while the ball is traveling downward.
A player kicks a soccer ball in a high arc toward the opponent's goal. When the soccer ball reaches its maximum height, how does its speed at this point compare to its initial speed? Assume air resistance is negligible
The speed at its highest point is less than its initial speed
Consider what happens when you jump up in the air. Which of the following is the most accurate statement?
When you push down on the earth with a force greater than your weight, the earth will push back with the same magnitude force and thus propel you into the air
A car accelerates from 8 m/s to 23 m/s at a rate of 3.0 m/s2. How far does it travel while accelerating?
78 m
Person B does twice the work of person A, and in one-half of the time . How does the power output of person B compare to person A?
Person B has four times the power output of person A
velocity differs from speed in that velocity indicates a particle's __________ of motion.
direction
An object is hanging by a string from the ceiling of an elevator. The elevator is slowing down while moving upward. What is the magnitude of the tension in the string?
The magnitude of the tension in the string is less than the magnitude of the weight of the object.
A football player kicks a football in a field goal attempt. When the football reaches its maximum height, what is the relationship between the direction of the velocity and acceleration vectors? Assume air resistance is negligible
At the maximum height, the velocity and acceleration vectors are perpendicular to each other.
A swimmer is determined to cross a river that flows due south with a strong current. Initially, the swimmer is on the west bank desiring to reach a camp directly across the river on the opposite bank. In which direction should the swimmer head?
The swimmer should swim northeast
Newtons second law: An object is moving in the absence of a net force. Which of the following best describes the object's motion?
The object will continue to move with a constant velocity
Unlike speed, velocity is a __________ quantity.
vector
A person applies a 50 N force on a crate, causing it to move horizontally at a constant speed through a distance of 10 m. What is the net work done on the crate?
The net work done on the crate is zero joules. Since the object is at constant speed, its acceleration is 0. Net work is equal to mass times distance times acceleration; therefore the answer is 0.
Your boat departs from the bank of a river that has a swift current parallel to its banks.
perpendicular to the current.
Which figure could represent the velocity versus time graph of a motorcycle whose speed is increasing?
If the net work done on an object is zero, what can you determine about the object's kinetic energy?
The object's kinetic energy remains the same.
For a projectile launched horizontally, which of the following best describes the vertical component of a projectile's velocity? Assume air resistance is negligible
The vertical component of the projectile's velocity continually increases
Once you have selected a coordinate system, you can express a two-dimensional vector using a pair of quantities known collectively as __________.
components
A graph depicts force versus position. What represents the work done by the force over the given displacement?
The work done is equal to the area under the curve.
A pilot releases a package from a plane flying horizontally at a constant speed. When the package reaches the ground below, what is the horizontal location of the plane with respect to the package? Assume air resistance is negligible
The plane will be located directly above the package.
A red water balloon is thrown horizontally from the top of a bridge. At the same instant, a yellow water balloon is dropped off the bridge from the same height. Compare the time of fall for the two balloons. Assume air resistance is negligible
The two balloons hit the ground at the same time.
An object weighing 20 N moves horizontally toward the right a distance of 5.0 m. What is the work done on the object by the force of gravity?
The work done on the object by the force of gravity is zero joules. Since gravity is perpendicular to the object, the net force is zero.
An object moves in a circular path at a constant speed. What is the relationship between the directions of the object's velocity and acceleration vectors?
The velocity and acceleration vectors are perpendicular
An object is hanging by a string from the ceiling of an elevator. The elevator is moving upward with a constant speed. What is the magnitude of the tension in the string?
The magnitude of the tension in the string is equal to the magnitude of the weight of the object.
A constant net force acts on an object. Which of the following best describes the object's motion?
The object is moving with a constant acceleration
What shape do we expect for a graph showing the position of a motorcycle versus time if the motorcycle is speeding up with a constant acceleration?
The position versus time graph is parabolic.
The same net force is applied to two different objects. The second object has twice the mass of the first object. Compare the acceleration of the two objects
The acceleration of object 1 is twice the acceleration of object 2
Two balls are dropped from the top of the Leaning Tower of Pisa. The second ball is dropped a fraction of a second after the first ball. As they continue to accelerate to the ground, the distance between them will
increase
Section 2
(20 cards)