Answer: To calculate the work done in pulling the chain to the top of the building, we need to determine the total weight of the chain and the distance it is lifted.
Given:
Length of the chain (L) = 40 ft
Weight per foot of the chain (w) = 5 lb/ft
Height of the building (h) = 120 ft
First, we calculate the total weight of the chain:
Total weight of the chain = Length of the chain × Weight per foot of the chain
Total weight of the chain = 40 ft × 5 lb/ft
Total weight of the chain = 200 lb
Next, we calculate the work done:
Work = Force × Distance
In this case, the force is the weight of the chain (200 lb), and the distance is the height of the building (120 ft). So we have:
Work = Total weight of the chain × Height of the building
Work = 200 lb × 120 ft
Work = 24,000 ft-lb
Therefore, the work done in pulling the chain to the top of the building is 24,000 foot-pounds (ft-lb).
Step-by-step explanation: :)