WAEC Physics 2012 Objective — Question 21
Question 21 of 50 from the West African Examinations Council (WAEC) Physics 2012 Objective paper, with the correct answer and a full explanation.
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A body is pulled over a distance of 500 m by a force of 20 N. If the power developed is 0.4 kW, calculate the time interval during which the force is applied.
- A. A. 0.2 s
- B. B. 2.5 s
- C. C. 25.0 sCorrect
- D. D. 250.0 s
Explanation
Power = Work done/time = (Force x distance)/time. Time = (Force x distance)/Power = (20x500)/400 = 25 s.
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