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# 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).

Related formulas

## Variables

 Ek Relativistic kinetic energy (J) m Mass (kg) c Speed of light v Velocity (m/sec)