Kinetic energy ($E_k$) can be expressed as:

If a body has mass and is moving, then the object is said to possess Kinetic energy. It is the energy possessed by the object due to its motion.

If a body has mass 'm' and is moving with the velocity 'v' then the kinetic energy can be expressed as

$E_k = \frac{1}{2} m{v}^2$