Answer:
Step-by-step explanation:
a. Arrow B is for the bigger person who is not active. 150J energy goes in, but only 10J is used in activity and the other 140J transforms to heat. The active smaller person uses 20J for activity, but needs only 100J/sec to keep their body working.
b. The diagrams both show that energy is conserved because the energy going in is equal to the sum of the energy transformed. For example, the top arrow shows: 100J = 20 J + 80 J