Basic of heat and temperature

Heat and temperature 

       

Hot and cold body

when we rubour hands for sometime they become warm.WhenA block slides on a rough surface it became warm. When The wheel slows down and so become warm when two vehicles collide with each other during an accident,they become very hot .when an aeroplane crashes ,it becomes so hot that it catches fire.

In each of example mechanical energy is lost and bodies in question become hot where are does the mechanical energy vanished?? It does into the internal energy of the body we conclude that the cold body absorb Energy to become hot .in other word A hot body has more internal energy that an otherwise identical cool body.

When A hot body is kept in contact with a cold body the cold body become a hot body and the hot body become cool body. The eternal energy of The horror body decreases. The eternal Energy of the cold body increases. Thus Energy transpired from the hot body to the cold body . Note is that no mechanical work is done during this transfer of energy. This is deferent from the case when we lift a ball vertically and the energy of the ball earth system increases or when a compressed spring relaxes and a block attached to its end speeds up.in the case of lifting a ball ,we do some work on the ball and the energy is increased by that amount.

This transfer of energy from a hot body to cold body is a non mechanical process .The energy that is transferred from one body to other body .