# Relativistic kinetic energy of rigid bodies

## Description

In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity.

In classical mechanics, the kinetic energy of a non-rotating object of mass m traveling at a speed v is equal to the mass multiplied by the square of the speed, multiplied by the constant 1/2.

In relativistic mechanics, this is a good approximation only when v is much less than the speed of light.

The work expended accelerating an object from rest to a relativistic speed is related to the velocity, the mass and the speed of light.

(The equation shows that the energy of an object approaches infinity as the velocity v approaches the speed of light c, thus it is impossible to accelerate an object across this boundary).

## Variables

E_{k} | Relativistic kinetic energy (J) |

m | Mass (kg) |

c | Speed of light |

v | Velocity (m/sec) |