Question

A bucket is attached the bottom of a line of rope that hangs off the top of a tall

building. The bucket weights 5 pounds, the rope weighs 1/2 pounds per foot, and

the bucket and rope hang 100 feet down from the top of the building. How much

work is done in pulling the rope and bucket up to the top of the building?

Answer 1

Work done for moving dh = Potential Energy = Wdh (W = weight, h = height)

Therefore, Workdone required = workdone for bucket + workdone for rope

Bucket,

Weigth is constant = 5 pounds

Therefore ,

Rope,

Weight depends on height = h X Weight per foot = h X (1/2) = h/2

Therefore ,

Thereby, total work done,