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?

Question

Physics

Joselyn Yu

12 June, 12:59

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?

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Answers (1)

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Corbin Bullock · Answer 1

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