A 100-hp car engine operates at about 15% efficiency. Assume the engine’s water temperature of 85oC is its cold-temperature (exhaust) reservoir and 495oC is its thermal “intake” temperature (the temperature of the exploding gas-air mixture).
(a) What is the ratio of its efficiency relative to its maximum possible (Carnot) efficiency?
(b) Estimate how much power (in watts) goes into moving the car, and how much heat, in joules and in kcal, is exhausted to the air in 1.0 h.