Question

A cyclist rides up a hill at a constant velocity. Determine the power developed by the cyclist if the length of the connecting rod of the pedal is $r = 25 \,cm$, the time of revolution of the rod is $t = 2 \,s$ and the mean force exerted by his foot on the pedal is $F = 15\, kgf$.

• A. 115.6 W
• B. 215.6 W
• C. 15.6 W
• D. 11 .56 W

Answer 1

Answer: (A)

115.6 W

Answer 2

Linear velocity, $v =r \omega=r \frac{2 \pi}{t}$ $=\frac{1}{4} \times \frac{2 \pi}{2}=\frac{\pi}{4} ms ^{-1}$ Power, $P=F \times v =(15 \times 9.8) \times \frac{\pi}{4}$ $=115.6\, W$