There is some ideal gas in a container moving with some velocity on a smooth surface and you suddenly stop it( say by using your hands) , will the temperature of the gas increase? It seems to me that since you're suddenly stopping it there is no work done (because of no displacement ) so the kinetic energy must change to internal and hence temperature of the gas will increase. Is this right? Now consider the same container but it is now moving on a rough surface . Assume there is a constant frictional force which stops it after travelling a certain distance. Now , will the temperature of the gas increase ? Now here I think since friction does work , the work will be equal to change in kinetic energy so the temperature will not increase . This seems strange. I think I'm not right. What is the difference between these two cases ? (Or , is there a difference?) Will the temperature change be same in both these cases ? (If at all it takes place).