OBJECT: To make an experimental determination of the mechanical equivalent of heat using a continuous flow calorimeter.
METHOD: A stream of water flowing through a glass tube is heated by an electric current passing through a heating element contained in the tube. The temperature difference between the water entering and leaving the tube depends upon the amount of energy supplied per unit time to the heating element (power input) and upon the mass of water flowing through the tube per unit time. A uniform rate of flow of water is maintained and several determinations of the temperature difference are made for corresponding values of the power input. From the measured rate of flow and the slope of a graph of power input versus temperature difference, the value of the mechanical equivalent of heat is determined.
