Question

Explain how it is possible for a ball to have kinetic and potential energy at the time?

Answer 1

There are numerous situations but I will explain the most common example.
A boy is holding a ball on top of a building of height. At this point, the ball possess gravitational potential energy and no kinetic energy as it is stationary.
He drops the ball down the building. During the duration of the fall, the ball's gravitational potential energy is converted to kinetic energy.

• Gravitational energy is given by mass x gravitational acceleration x height of ball relative to ground.

Thus, as the ball's height above ground decreases as it falls down, it loses GPE.

• Due to the Law of Conservation of Energy, the total energy of the ball remains unchanged. Thus, the loss in GPE has to be converted to another form of energy.
• The ball gains kinetic energy as it's velocity increases due to gravitational acceleration. (The ball also gains heat energy due to air friction, but shouldn't be too significant.)

Throughout the period of the fall, the ball possesses both GPE and KE.
When the ball is just about to land on the ground, it possesses no GPE and maximum KE.