Kinetic energy: It is the energy possessed by a body due to its motion.
Every moving body possess the energy in the form of kinetic energy.
Demonstration of moving object possess energy:
Hitting of a nail with a hammer. In this case the kinetic energy of hammer is used to drive nail to wall.
Work: During the hitting of nail, it gets displaced and penetrates into wall. In this case, the product of
force applied on the nail and (due to kinetic energy of hammer) and displacement of the nail gives the work done.