The food we eat contains potential energy, and our body stores this energy until we use it when we work. This is how potential energy changes into kinetic energy here is a story of how energy can change.
Kinetic energy is the energy possessed by a moving object. That is energy gained by body due to virtue of its motion.It generally comes into picture when some work is done onto the body to set it in motion. We calculate it as KE = 12 mv2. Potential energy is the energy stored within a physical system as a result of the position or configuration of the different parts of that system. It has the potential to be converted into other forms of energy such as kinetic energy and to do work in the process. PE = mgh (h is the height of the body from reference point). When no other form of energy is created or lost in motion of a body then from the law of Conservation of energy we can say that Potential energy of body converts to Kinetic Energy.