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# Horsepower is a unit of power; one horsepower (1 hp) is equivalent to 745 watts. The world record for climbing a 25-feet rope was set by Garvin Smith in Los Angeles in 1947, when he climbed the 25 feet in 4.7 seconds. Assuming that Mr. Smith has a mass of 65 kg, calculate the average power (in both watts and horsepower) that he generated during his climb.

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$1\text{feet}=0.305\text{m}$

$25\text{feet}{\cdot}0.305=7.625\text{m}$

First we need to calculate the energy:

$E=m{\cdot}g{\cdot}h$

$E=65\text{kg}{\cdot}9.81\text{ms}^{-2}{\cdot}7.625\text{m}$

$E=4862.08\text{J}$

Now we can calculate average power:

$Average power={\dfrac{Work done}{Time taken}}$

$Average power={\dfrac{4862.08\text{J}}{4.7\text{s}}}$

$Average power=1034.49\text{W}$

$1\text{hp}=745\text{W}$

$1\text{W}=0.00134\text{hp}$

$1034.49\text{W}{\cdot}0.00134=1.386\text{hp}$

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