what is kinetic energy?

Brief Explanations:

Kinetic energy is the energy an object possesses due to its motion. It depends on the mass and velocity of the object, with the formula $KE=\frac{1}{2}mv^{2}$, where $m$ is mass and $v$ is velocity.

Answer:

Kinetic energy is the energy of motion, calculated by $KE = \frac{1}{2}mv^{2}$, where $m$ is the mass of the object and $v$ is its velocity.