Kinetic energy

Kinetic energy is the energy possessed by a body purely by virtue of its motion. Every moving object has kinetic energy; an object at rest has none. Because a moving body can push, deform, or otherwise act on whatever it strikes, kinetic energy is measured operationally by the amount of work the body can perform before it is brought to rest.

The kinetic energy of a body of mass $m$ moving with speed $v$ is

$KE = \tfrac{1}{2}mv^2$ …