Answer:
From gravitational potential to kinetic energy
Step-by-step explanation:
There are two types of energy involved in this process:
- Gravitational potential energy: it is the energy possessed by the rock due to its position. It is given by
where
m is the mass of the rock
g is the acceleration due to gravity
h is the height of the rock above the ground
- Kinetic energy: it is the energy possessed by the rock due to its motion. It is given by
where
m is the mass of the rock
v is its speed
At the beginning, when the rock is on top of the cliff, it has GPE (because its height h is non-zero), while being at rest, its KE is zero.
As the rock falls down, its GPE decreases (as the height h decreases), and at the same time, its KE increases (as the speed increases).
So, the energy has been converted from gravitational potential to kinetic energy.