in this experiment, the friction and agitation of the paddle-wheel on the body of water caused heat to be generated which, in turn, increased the temperature of water. both the temperature change ∆t of the water and the height of the fall ∆h of the weight mg were recorded. using these values, joule was able to determine the mechanical equivalent of heat. joule estimated a mechanical equivalent of heat to be 819 ft•lbf/btu (4.41 j/cal). the modern day definitions of heat, work, temperature, and energy all have connection to this experiment.