# Kinetic Energy

Kinetic energy is the energy an object possesses due to its motion. It is defined as the work necessary to accelerate a body of a given mass from rest to a given velocity. Kinetic energy, as shown by the formula below, is one half the product of mass (m) and velocity squared (v^{2}). Kinetic energy is measured in joules (kg·m^{2}/s^{2}).

**E**_{K} = 1/2 m v^{2} kinetic energy E K is equal to half of the mass m, times the speed v to the square

**E**

_{K}= 1/2 m v^{2}For example, when a rock containing potential energy due to being high on a cliff falls, its potential energy is converted into kinetic energy while the rock falls to the ground. Similarly, when a car is on a highway, the chemical energy in the car's fuel is converted into the kinetic energy of the car's motion. Any moving body maintains a constant kinetic energy as long as its speed does not change. Together, potential energy and kinetic energy make up mechanical energy.

**Figure 1:** Potential and Kinetic Energy