Section 1
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Horsepower
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Last updated
6 years ago
Date created
Mar 1, 2020
Cards (68)
Section 1
(50 cards)
Horsepower
a common unit of power, equal to 76 watts
What type of machine is a knife?
wedge
What are the units for work?
N-meter or J
formula for work output
resistance force x resistance distance
Watt
the SI unit for power, equal to 1 Joule per second
What does a simple machine has MA greater than 1 do?
effort force is reduced while effort distance is increased
How can you exert more power without doing more work?
same amount of work in less time
Mechanical advantage
the number of times a machine increases the input force
What type of machine is a block and tackle a form of?
pulley
What typically happens to MA of a pulley system as movable pulleys are added?
increases
Work
the product of distance and the force in the direction an object moves
What does a fixed pulley do to the effort force?
changes direction of the effort force
machines can _______ effort force
multiply
IMA of 3rd class lever with effort force at 50 cm, fulcrum at 20 cm, and resistance at 90 cm
30 / 70 = 0.43
machines can multiply _______
distance
What type of machine is a screwdriver?
wheel and axle
Machine
A device that makes work easier
Joule
the SI unit for work
What force is required when 64 J of work is done and the distance is 16 m?
4 N
If 200 N of force is applied to do 100 J of work in 2 seconds, what is the distance?
0.5 m
Work output
the work done by a machine as the output force acts through the output distance
Input force
the force exerted on a machine
Why is work output always less than work input?
Some of the energy is used to overcome the friction
What typically happens to MA of a pulley system as fixed pulleys are added?
stays the same
formula for work
force x distance
How much work do you do when you stand for 5 minutes at the bus stop with a 40 N backpack on your back?
0
Work input
work done on a machine as the input force acts through the input distance
formula for efficiency
Work output / Work input x 100%
What is the unit for power?
watts
IMA of 1st class lever with effort force at 20 cm, fulcrum at 50 cm, and resistance at 90 cm
30 / 40 = 0.75
Input distance
the distance through which an input force acts in a machine
lever with resistance in middle
2nd class
formula for work input
effort force x effort distance
What type of machine is stairs?
inclined plane
If 200 N of force is applied to do 100 J of work in 2 seconds, what is the power?
50 watts
What does a movable pulley do to the effort force?
multiplies the effort force
formula for power (P)
Work (W) / time (t)
What happens to efficiency as more pulleys are added to a pulley system?
decreases
IMA of 2nd class lever with effort force at 20 cm, fulcrum at 90 cm, and resistance at 50 cm
70 / 40 = 1.75
Output distance
the distance the output force acts through in a machine
What does a simple machine has MA less than 1 do?
multiply effort distance
What is the formula for ideal mechanical advantage?
input distance / output distance
lever with fulcrum in middle
1st class
What is the formula for actual mechanical advantage?
resistance force / effort force
Power
the rate at which work is done
What does a simple machine has a MA of 1 do?
changes the direction of the effort force
What type of machine is a broom?
lever
machines can _______ of force
change direction
Output force
the force exerted by a machine
lever with effort in middle
3rd class
Section 2
(18 cards)