Which of the following represents heat energy represented in mechanical work?

Heat energy can be converted into mechanical work, and both Joules and British Thermal Units (BTUs) are units that can express energy, including heat energy. Joules are the SI unit of energy and are commonly used in physics to quantify work, heat, and energy. Since mechanical work is defined in joules when energy is converted into physical actions, this unit adequately represents heat energy in mechanical work contexts.

Similarly, British Thermal Units (BTUs) serve as a measure of heat energy specifically in the context of heating and cooling systems, with one BTU defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. When heat energy is converted to perform work in mechanical applications, BTUs can also express that energy equivalently.

Therefore, since both Joules and BTUs can represent heat energy in the context of mechanical work, the answer identifies both units as valid representations. The inclusion of both units emphasizes the versatility of energy measurements in different systems and applications, covering both the metric and imperial measurement systems.