The Law Of Conservation Of Energy

The statement below is specified in many texts as another formulation of the first Law:

“The energy of a system stays constant when the system is isolated from its surroundings as regards heat and work”.

In another words, the energy of an isolated system, like our universe, stays steady. This leads to another statements like: “Energy can neither be created nor destroyed”. It is noticed that the law of conservation of energy is less common than the first Law.

                                           Q – W = ΔE      

The equation above illustrate that whenever Q = 0 and W = 0, ΔE = 0, that is embodied in the Law of Conservation of Energy; this, although, does not state how the energy changes whenever Q & W are not zero.