Exercise

Heat flows from the warm to the cold body because the energy state is higher.

         Heat flow moves energy from a higher temperature to a lower temperature. The bigger the difference in temperature between the two objects, the faster heat flows between them. When the temperature is the same there is no change in energy due to heat flow. Heat flows from a hot body to a cold body until thermal equilibrium is reached.

        Radiation and conduction are the two methods of heat transfer. Convection is a special type of conduction.

Heat:

         Heat is the energy that is transferred from one body to the other in thermal contact with each other as a result of the difference in temperature between them.

Temperature:

       The temperature of a body is the degree of hotness or coldness of the body.

Internal energy:

              The sum of kinetic energy and potential energy associated with the atoms, molecules, and particles of a body is called internal energy.
              The internal energy of a body depends on many factors such as the mass of the body, kinetic and potential energy of molecules, etc.

                                    $\triangle U$ = Q – W

Where:     $\triangle U$ = internal energy,   Q = Heat and W = work done