Question 11
Work, Energy and PowerHow long will it take a 60 kg man to climb a height of 22 m if he expended energy at the rate of 0.25 kW? [g = 10 m s−2]
- A.5.3 s
- B.34.5 s
- C.41.6 s
- D.52.8 s.
Show the answer and explanation
Answer: D (52.8 s.)
Explanation
Work = mgh = 60 × 10 × 22 = 13 200 J. Time = 13 200 ÷ 250 = 52.8 s.