The energy conversion or the energy transformation is the process of changing one form of energy to another , the energy produces certain changes within a system , Changes in the total energy of systems can only be accomplished by adding or removing the energy from them as the energy is a quantity which is conserved ( unchanging ) .
The internal combustion engine in the car converts the potential chemical energy in gasoline and oxygen into thermal energy which is transformed into the mechanical energy that accelerates the vehicle ( increasing its kinetic energy ) by causing the pressure and performing the work on the pistons .
