A 44-kg woman cheats on her diet and eats a 488-Calorie (488 kcal) jelly doughnu

Question

A 44-kg woman cheats on her diet and eats a 488-Calorie (488 kcal) jelly doughnut 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 27% efficient in converting chemical energy to mechanical energy, how many stairs must the woman climb to work off her breakfast?
_________stairs

Explanation / Answer

a.

1 calorie = 4.18 J

equivelant jule in one jelly = 488 * 4.18 = 2039.84 KJ

b. no of stairs = 2039.84 *10^3 / (44*9.81* 0.15) = 31500.............. stairs

C. no of stairs = 27% * 2039.84*10^3/( 44*9.81*0.15) = 8506 ...... stairs

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

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