Which best describes the heat that you can feel on the engine of a running car?

A running car’s engine converts some fuel energy into useful work, but not all of it. The heat you feel coming from the engine is waste heat that escapes to the surroundings, so it is generally unusable for moving the car. Therefore, the best choice is “The heat is unusable and lost to the surroundings.”

AI-written and checked against the verified answer.