Question

A pail in a water well is hoisted by means of a frictionless winch, which consists of a spool and a hand crank. When Jill turns the winch at her fastest water-fetching rate, she can lift the pail the 20.0 m to the top in 14.0 s. Calculate the average power supplied by Jill's muscles during the upward ascent. Assume the pail of water when full has a mass of 7.20 kg.

Answer 1

Answer:

The average power supplied is 100.8 W.

Explanation:

Given that,

Height = 20.0 m

Time = 14.0 s

Mass = 7.20 kg

We need to calculate the average power

Using formula of average power

power = change in potential energy divided by time

$P=\dfrac{mgh}{t}$

Where, h = height

t = time

m = mass

Put the value into the formula

$P=\dfrac{7.20\times9.8\times20.0}{14.0}$

$P=100.8\ W$

Hence. The average power supplied is 100.8 W.