A 44 kg woman cheats on her diet and eats a 612 Calorie (612 kcal) jelly donut f

Question

A 44 kg woman cheats on her diet and eats a 612 Calorie (612 kcal) jelly donut for breakfast.

(a) How many joules of energy are the equivalent of one jelly doughnut? in 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.? in stairs?

(c) If the human body is only 27% efficient in converting chemical energy to mechanical energy, how many stairs must the woman climb to work off her breakfast? stairs?

Explanation / Answer

Just change numericals in this proble you will get the answer

(a) Since 1 cal = 4.184 J

547 kcal = 547,000 cal = 2.289 x 10^6 joules

(b) Height of 1 stair step is 0.15 m

E = mgh = 2.289 x 10^6 joules

m = 59 kg (weight of the woman)
g = 9.82 m/s

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.