POTENTIAL ENERGY QUESTIONS
1. A crane lifts a 1500 kg car 20.0 m straight up.
(a) How much gravitational potential energy does the car gain relative to the
ground?
(b) How much work does the crane do?
2. A 0.0500 kg apple hangs from a 6.00 m tall tree.
(a) How much gravitational potential energy does the apple possess
relative to the ground?
(b) If the apple falls, how much potential energy will it lose?
(c) How much kinetic energy will the falling apple possess?
3. A 62.0 kg diver is standing on a diving board, 10.0 m above the water.
(a) How much gravitational potential energy does the diver possess at
this height, relative to the water?
(b) How much gravitational potential energy does the diver lose when
they jump from the diving board to the water?
(c) How much kinetic energy does the diver possess as they fall towards the water?
(d) what speed does the diver travel in the air, before they hit the water?
Summary:
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Gravitational potential energy is possessed by objects based on its position relative to
a reference level, which is often the ground. Eg = mgh, where h is the height above the
chosen reference level.
When an object (at rest) is released from a certain height, it travels towards the earth
with a quantity of kinetic energy of equal magnitude to the gravitational potential
energy.
Answers:
1. a) 2.9 x 105 J
2. a) 2.94 J
3. a) 6080 J
b) 2.9 x 105 J
b) 2.94 J
b) 6080 J
c) 2.94 J
c) 6080 J
d) 14.0 m/s