A ball falls from the top of a building, through the air (air friction is present), to the ground below. How does the kinetic energy (K) just before striking the ground compare to the potential energy (U) at the top of the building?

Question

Quizplus · Accepted Answer

As the ball falls through the air, some of its potential energy is converted to kinetic energy. However, air friction causes some of this energy to be lost as heat, sound, and other forms of energy, so the kinetic energy of the ball just before striking the ground is always less than the potential energy it had at the top of the building. Therefore, K is less than U.

A Ball Falls from the Top of a Building, Through