A 45 kg woman cheats on her diet and eats a 439 Calorie (439 kcal) jelly donut for breakfast.
(a) How many joules of energy are the equivalent of one jelly doughnut?
J
(b) How many stairs must the woman climb to perform an amount of mechanical work equivalent to the food energy in one jelly doughnut? Assume the height of a single stair is 15 cm.
stairs
(c) If the human body is only 28% efficient in converting chemical energy to mechanical energy, how many stairs must the woman climb to work off her breakfast?
stairs