**Kinetic energy**, also known as motion energy, is a physical quantity that represents the energy of an object due to its motion.
The kinetic energy of an object is equal to the work done to accelerate it and depends on the mass and velocity of the object:

$$E_k=\frac{mv^{2}}{2}$$

where,

m— mass of the object;

v— velocity.

For a body rotating about a fixed axis, the kinetic energy can be found using the formula:

$$E_k=\frac{I\omega^{2}}{2}$$

where,

I— moment of inertia of the body about the specified axis;

ω— angular velocity.

The **unit of kinetic energy** in the SI system is the **joule** (J).