I'm not sure if I'm interpreting this question correctly A heat engine operated between 40C and 380C. Being a real engine, it efficiency is only 60% of that theoretically possible for a Carnot engine at these temperatures. If it absorbs heat at a rate of 60kW at what rate does it exhaust heat? So should I be finding the ideal (Carnot engine) and then taking 60% of that? ideal = 1-Tl/Th = 1- (313K/653K) = 0.52 so then I figured it runs at 60% of ideal so e should be 0.312 Is this right or is e just 60% ??