Question
(a) What is the efficiency of an out-of-condition professor who does $2.10 \times 10^5 \textrm{ J}$ of useful work while metabolizing 500 kcal of food energy? (b) How many food calories would a well-conditioned athlete metabolize in doing the same work with an efficiency of 20%?

a) $0.100$

b) $251 \textrm{ kcal}$

Solution Video