The cylinder is cooled so that, when it is heated by friction, the midpoint of the high and low temperatures will be at room temperature. In the first half of the experiment, therefore, heat will be transferred from the room air into the cooler cylinder. As the cylinder heats beyond room temperature though, heat will be transferred out of the cylinder back into the room atmosphere. By letting the change in cylinder temperature be symmetrical about the room temperature, the quantity of heat transferred to and from the cylinder and room should be approximately equal. Â While the cylinder is cooling, plan the desired.
