Could a simple machine such as a lever, a pulley system or a hydraulic jack be considered a heat engine? Explain your answer.

Question

I feel that its the hydraulic jack because if friction is created, heat is also created. I'm not sure though.

Answer 1

There may be friction in a hydraulic jack, and a bit of heat produced, but that does not make it a heat engine.

A heat engine converts heat to mechanical energy. None of the things on your list do that.

Answer 2

Pascal's principle is the foundation of modern hydraulics