Question

A heavy rope, 60 ft long, weighs 0.7 lb/ft and hangs over the edge of a building 140 ft high. (a) How much work W is done in pulling the rope to the top of the building?

Answer 1

Answer:

5880lb-ft of work is done

Explanation:

The length of the heavy rope is given as 60ft and the weight per length is 0.7lb/ft.

Therefore, the total weight of the heavy rope is

60×0.7 =42lb.

The work done in pulling the heavy rope to the top of the building is w = Fd.

Where

F is force is measured in pounds;42lb

d is distance through which the heavy rope is to be pulled measured in feet; 140ft

w= 42lb×140ft= 5880lb-ft