Question

Explain the meaning of K.E. with examples.

Answer 1

Hint: A body in motion possesses kinetic energy.
Kinetic energy is not created or destroyed. Although a body at its rest position has zero kinetic energy, it has potential energy, which is converted into kinetic energy during its motion. Similarly when a moving body comes to rest, its kinetic energy is converted into potential energy, and the body stops.

Complete step by step answer:
The kinetic energy of a moving body is measured by the amount of work, which has been done in bringing the body from the rest position to its present position, or which the body can do in going from its present position to the rest position.
For example, consider a car initially at rest. If force is applied in it, it starts moving under an acceleration. The body acquires a velocity in moving a distance. Thus, the body possesses kinetic energy during its motion.
Similarly, a bullet when fired from a gun moves with a certain velocity before it strikes an obstacle and comes to rest. The energy possessed by the moving bullet is called kinetic energy.
Again, when a body falls from a height, it possesses kinetic energy during its downward motion. Similarly, a rocket when ignited accelerates out of the atmosphere with kinetic energy.
A pendulum possesses kinetic energy when its bob is in motion, moving with a certain velocity. A swing in motion also has kinetic energy, due to it’s to and fro motion.

So, the correct answer is “Option A”.

Note:
The kinetic energy of a body may not remain the same at all instant. It depends on the body’s velocity at that instant. The kinetic energy of a body is independent of the direction.According to the principle of Conservation of Energy, “energy can neither be created nor can be destroyed, but can only be converted from one form to another”.