Thermal Properties Of Matter

Gases like water vapours, chlorofluoro carbons and oxides of nitrogen have the ability to entrap solar radiation which increase the temperature of atmosphere. This is called green house effect.

The root mean square velocity of the molecules of a gas is directly proportional to the square root of absolute temperature of gas, that is, where is gas constant, and is mass. From the above relation it is evident that if absolute temperature of the gas becomes zero then the motion of molecules will cease , Hence according to kinetic theory absolute zero is that temperature at which the motion of all the molecules of the gas stops. It is also clear that absolute temperature can never be negative, because can never be negative. Thus, no temperature is possible below the absolute zero.

The rate of heat loss is proportional to the difference in temperature. The difference of temperature between the tea in cup and the surrounding is reduced, so it loses less heat, the tea in cup loses more heat because of large temperature difference. Hence, the tea in cup A will be hotter.