Final answer:
Gravitational potential energy and kinetic energy change as the rock rolls down the hill.
Step-by-step explanation:
As a rock rolls down a hill, the types of energy that are changing are gravitational potential energy and kinetic energy.
Gravitational potential energy is the energy an object possesses due to its height above the ground. As the rock rolls down the hill, it loses gravitational potential energy.
Kinetic energy is the energy of motion. As the rock gains speed while rolling down the hill, its kinetic energy increases. At the bottom of the hill, when the rock comes to a stop, its kinetic energy is maximum while its gravitational potential energy is minimum.
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