Jill pulls on a rope to lift a 12 kg pail out of a well, while the clumsy Jack watches. For a 10.0 meter segment of the lift, she lifts the bucket straight up at constant speed. How much power is required to complete this task in 5.0 seconds?
Definition of power is the amount of work done per unit of time: [tex]P=\frac{W}{t}[/tex] We need to calculate the work done by Jill. Work is defined as the force acting along the path: [tex]W=F\cdot h[/tex] In this case, Jill is working against the force of gravity along the path of 10 meters: [tex]W=mgh=12\cdot9.81\cdot 10=1177.2 J[/tex] Now we can calculate the power: [tex]P=\frac{1177.2}{5}= 235.44 W[/tex]
