Question

The man of the preceding problem consumes approximately 1.05×107J (2500 food calories) of energy per day in maintaining a constant weight. What is the average power he produces over a day? Compare this with his power production when he runs up the stairs.

a) 121.5 W, Greater than running up the stairs
b) 120.5 W, Less than running up the stairs
c) 124.0 W, Greater than running up the stairs
d) 122.2 W, Equal to running up the stairs

Answer 1

The man produces an average power of 121.5 W over an entire day. This is based on the total energy consumed of 1.05×107J divided by the number of seconds in one day. The power when running up the stairs is likely higher due to the concentrated effort over a shorter time.

Step-by-step explanation:

The average power a man produces over a day after consuming approximately 1.05×107J (2500 food calories) can be calculated by dividing the total energy by the number of seconds in one day. The total energy in joules is 1.05×107J and there are 86,400 seconds in a day (24 hours × 60 minutes × 60 seconds).

Power = Energy / Time = 1.05×107J / 86,400 s ≈ 121.5 W

Therefore, the correct answer is (a) 121.5 W. To compare this with the power production when he runs up the stairs, you need to know two things: the amount of energy used to run up the stairs and the time it took. The power produced during this activity will likely be greater than the average daily power output because physical activities like running up stairs are done over a short period and will require a higher power output compared to the constant low-level power output throughout the day.