Question

a steel girder weighting 700 lb is hoisted from gund level to the roof of a 70-ft building using a chain that weighs 4lb/running foot. Find the work done

Answer 1

Answer:

66.475kJ

Explanation:

Work done is the product of the force and perpendicular distance in direction of the force.

Work done = Force × distance

Given

Weight = 700lb

Distance = 70ft

1lb force = 4.448N

700lb force = 700(4.448) = 3113.6N

Distance = 70(0.305) = 21.35m

Work done = 3113.6×21.35

Work done ≈ 66,475Joules

Work done = 66.475kJ