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WorksheetsMachines and Energy Test c 13 Review
Total questions: 15
Worksheet time: 8mins
A bus engine transfers chemical potential energy into ______ so that the bus moves.
kinetic energy
potential gravitational energy
electrical energy
thermal energy
Increasing the speed of an object ______ its potential energy.
increases
changes
does not affect
decreases
When a machine is used to do work, the force applied by the machine is called the
input force
output force
effort force
potential force
As an object falls its potential energy is
lost to the air above it.
converted into chemical energy.
lost to the air around it.
converted to kinetic energy.
Lowering an object decreases its
air resistance.
gravitational pull.
potential energy.
chemical energy.
A slanted surface used to raise an object is a(n)
inclined plane.
screw.
effort ramp.
efficiency board.
The rate at which work is done is called
force.
power.
effort time.
efficiency.
An inclined plane wrapped around a cylindrical post is a ____.
ramp
screw
block and tackle
lever
The unit of power is the
joule
m/s
watt
second
Three of the following simple machines are basically the same. Which one does NOT belong with the group?
lever
pulley
wedge
wheel and axle
A can opener consists of three simple machine. Which of the folllowing isn't included in the 3?
wheel and axle
wedge
pulley
lever
A student does 686 J of work on an object in 3.1 seconds. What is the power output of the student?
54 W
60 W
221 W
450 W
What is the mechanical advantage of a ramp that is 6.0 m long and 1.5 m tall?
4
5
6
7
Alice and Jim calculate that they must do 1,800 J of work to push a piano up a ramp. However, because they must also overcome friction, they actually must do 2,400 J of work. What is the efficiency of the ramp?
10%
25%
50%
75%
If a weight lifter is holding barbells above his head, what does he have to do to perform work?
stand still
lower barbells
move barbells sideways
step forward
