The law of conservation of energy states that the total energy of an isolated system is always conserved. It signifies that energy can only be converted from one form to another. For example, the stored potential energy of water at the top of a cliff gets converted to kinetic energy when it falls. Similarly, when a log of wood is burned, potential energy stored in the wood is converted to kinetic energy in the form of light and heat. Mathematically, the law of conservation of energy is represented as the sum of the change in kinetic energy, potential energy, and internal energy as equal to zero. In other words, if one form of energy decreases, it is compensated by an increase in other forms of energy.