Kinetic energy is used by exploiting the motion of an object. For example, the energy of a moving piston in an automotive engine provides transportation. The kinetic energy of moving water powers hydroelectric dams that provide electricity.
There are many uses of kinetic energy in sports. A pitcher transfers the kinetic energy of his pitching arm to a baseball. A batter uses the kinetic energy of a swinging bat to amplify the energy in a pitched ball to get on base or score a run. Similarly, a tennis player swings a racket to amplify the kinetic energy of a tennis ball.
Creating electricity through the motion of wind is another example of how kinetic energy is used. Wind turbines change the kinetic energy of wind to rotary motion that turns electrical generators. Wind turbines can be used not only to generate electricity, but also to pump water from underground wells.
Kinetic energy is the energy of an object in motion and is relative to the object's mass and velocity. The kinetic energy of water or wind is based on the accumulation of the mass of many small particles working together. Kinetic energy can be transferred or stored, but is never lost, as defined by the law of conservation of energy.