Question: A 70 kilogram person is walking up a 15 % grade hill. Plot the fuel consumption of the person in watts vs. speed from 1 to 7 kilometers per hour in steps of 1. On the same plot, plot the useful work power output of the person lifting them self against gravity. Note that a 15 % grade means climbing 15 feet for every 100 feet of horizontal travel, so you will have to a little trigonometry here.

Part A: What is the efficiency of the person converting fuel power into useful work (lifting power)?

Part B: Where does the lost energy go?

Part C: Could you figure out a way to measure the lost energy?

Show how you get the answer, so that I can better understand how to do it.