How is Energy Transformed?

What is energy and how do we change it? Energy is a fundamental concept of science involving the capacity for doing work. Kinetic or mechanical energy is the most obvious form of energy. It is defined as

E = ½ mv²

where

E = energy (expressed in joules)

m = mass of the moving object (in kilograms)

v = velocity (in meters per second)

Energy can also be stored in chemical and nuclear substances or in the water behind a dam. In these quiescent states it is called potential energy. If the potential energy in a substance is abundant and easily released, the energy-rich substance is called a fuel.