- #1

- 14

- 0

## Homework Statement

While running up stairs at a (vertical) rate of 0.30 m/s, a man of 70 kg generates waste heat at a rate of 1300 J/s. What efficiency for the human body can you deduce from this?

## Homework Equations

efficiency of heat engine=e=[itex]\frac{W}{Q

_{1}}[/itex]=[itex]\frac{Q

_{1}-Q

_{2}}{Q

_{2}}[/itex]=1-[itex]\frac{Q

_{2}}{Q

_{1}}[/itex]

## The Attempt at a Solution

Kinetic energy= [itex]\frac{1}{2}[/itex](70)(.30)

^{2}= 3.15

e[itex]\frac{3.15}{1300}[/itex]=0.0024 X 100=0.024 %

According to the book the answer is 14%

How do I get to this answer?