# Can energy be created or destroyed?

The law of conservation of energy states that in an isolated system the total energy remains constant—it is said to be conserved over time. Energy can neither be created nor be destroyed, but it can change from one form to another form. for instance,

1. Mechanical energy, such as the kinetic energy of motion, can be converted to heat energy

eg.  in the heating of a car’s brakes when it slows down. Chemical energy in the gasoline of the car can be converted into both heat energy in the exhaust and heating the engine, and into mechanical energy to move the car.

2.Potential energy such as the gravitational potential energy stored in an object which is on a high shelf, can be converted into kinetic energy as the object falls down.

3.Electrical energy can be converted to heat or mechanical energy or sound energy in a variety of useful ways around the house using common appliances.

From these examples it is evident that energy can neither be created nor destroyed it can only be changed from one form to another desired form.

Approved by eNotes Editorial Team

No, energy cannot be created or destroyed. This is known by the law of conservation of energy which states that the total energy of an isolated system remains constant over time, i.e. energy is conserved.

Energy can be converted from one form into another, e.g. from chemical to heat to kinetic in a combustion engine, or from kinetic to electrical in an electric generator. Also, we know that mass and energy are two forms of the same thing from Einstein's equation `E=mc^2.` This fact is applied in nuclear power plants and nuclear weapons which turn mass into energy (mainly heat) by using nuclear fission or fusion.

If you want to know more on the topic I suggest you read History and root of the principle of the conservation of energy.