2. The Mechanical Equivalent of Heat Unit for heat energy: 1 Btu (raise the temperature of one pound of water by one degree Fahrenheit) Unit for mechanical energy: 1 foot-pound (raise one pound of water one foot higher) Which one is larger? 1 Btu =778 foot-pound You can lifting a one-pound weight 778 feet into the air with the energy released by the burning of only one match Capture the heat energy of the fuel and turn it into mechanical energy The possibility of easing human labor by utilizing heat sources has been the driving force behind a long history of development of what we now call heat engines2. The Mechanical Equivalent of Heat Which one is larger? 1 Btu = 778 foot-pound You can lifting a one-pound weight 778 feet into the air with the energy released by the burning of only one match. Capture the heat energy of the fuel and turn it into mechanical energy. The possibility of easing human labor by utilizing heat sources has been the driving force behind a long history of development of what we now call heat engines. Unit for heat energy: 1Btu (raise the temperature of one pound of water by one degree Fahrenheit) Unit for mechanical energy: 1 foot-pound (raise one pound of water one foot higher)