Problem 3.

A cat stuck up a tree and has 500 J gravitational potential energy. It then falls. Find the kinetic energy of the cat just before it is caught by the owner. Find the kinetic energy of the cat after it is caught by the owner. Find the wasted energy (after cat is caught by the owner).

Disregard air resistance.

Solution:

As the cat falls there is a transformation of potential energy into kinetic energy. Just before the cat is caught by the owner the kinetic energy is exactly equal to the initial potential energy = 500 J.

After the cat is caught by the owner, its velocity is 0. It means that the kinetic energy is equal to 0 (no motion).

The wasted energy is defined as an initial energy minus the final energy. The initial energy is 500 J, the final energy is 0. Then the wasted energy is 500 J.