In physics, **kinetic energy** is energy possessed by a body by virtue of its motion. In Newtonian mechanics, a body with mass *m*, moving in a straight line with velocity *v*, has a *translational kinetic energy* of

- .

- ,

In Einstein's relativistic mechanics, the kinetic energy of a body is

Where gravity is weak, and objects move at much slower velocities than light (e.g. in everyday phenomena on Earth), Newton's formula is an excellent approximation of relativistic kinetic energy.

See also: