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WorksheetsWork and Energy
Total questions: 20
Worksheet time: 2hrs 47mins
Which sequence describes the energy conversions
in a car’s engine?
chemical to thermal to mechanical
mechanical to thermal to chemical
thermal to mechanical to chemical
kinetic to potential to mechanical
What is the potential energy of a 10.0 kg weight suspended 3.0 m above the ground?
3.3 J
30 J
290 J
2900J
What is the kinetic energy of a 1000 kg car traveling at 20 m/s _______.
200000 J
20000 J
400000 J
20000000 J
According to the law of conservation of energy
energy cannot be created or destroyed
everything eventually stops moving
potential energy must be converted into kinetic energy
kinetic energy plus potential energy equals mechanical energy
The gravitational potential energy of a cucumber
Earth system changes when which factor changes?
the cucumber's speed
the cucumber's mass
the cucumber's temperature
the cucumber's length
Which cannot be done by a machine?
increase force
increase work
change direction of a force
increase velocity
Which factor increases as the efficiency of a
machine increases?
work input
work output
friction
input force
Friction causes mechanical energy to be
converted into which form?
thermal energy
kinetic energy
nuclear energy
potential energy
What term indicates the number of times a machine multiplies the input force?
efficiency
power
mechanical advantage
resistance
The kinetic energy from an object’s motion
always changes when which factor changes
the object's chemical potential energy
the objects volume
the object's direction of motion
the object's speed
What is the S.I unit of work?
N.m2
(Kg.m2) / s2
J/m
J
Work is zero if the force has a component in the direction opposite of motion.
True
False
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 object is moving with a constant velocity.
The object is slowing down.
The object is at rest; its position is constant.
Then how much work is done if it takes 20N to move a box 10 meters
