A 65 kg woman cheats on her diet and eats a 537 Calorie (537 kcal) jelly donut f

Question

A 65 kg woman cheats on her diet and eats a 537 Calorie (537 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 20% efficient in converting chemical energy to mechanical energy, how many stairs must the woman climb to work off her breakfast?

I have parts A and B correct. I just need help with part C. Please show work, I am confused.

Explanation / Answer

1calorie =4.18j

a)537 calories =2244.66kj

b)nmgh =2244.66

n x 65 x 9.8 x0.15 =2244.66 x 1000

n =23491

c)20 percent of steps =4698

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

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