You decide to use your body as a carnot heat engine. the operating gas is in a tube with one end in your mouth (where the temperature is 37.0c) and the other end at the surface of your skin, at 30. a, what is the maximum efficiency of such a heat engine? would it be a very useful engine? ans: in 2.26% b, suppose you want to use this human engine to lift a 2.80kg box from the floor to a tabletop 1.40m above the floor. how much must you increase the gravitational potential ,suppose you want to use this human engine to lift a 2.80 box from the floor to a tabletop 1.40 above the floor. how much heat input is needed to accomplish ,how many 350 (those are food calories, remember) candy bars must you eat to lift the box in this way? recall that 80.0 of the food energy goes into heat.