Final answer:
The total work done to push the shipping container filled with a fluid of specific gravity 0.85 across the lab for a distance of 20 feet is calculated as 39.20 kJ.
Step-by-step explanation:
To calculate the work done to push a completely filled shipping container, we first need to determine the total weight of the container with the fluid inside it. The volume of the container is given by multiplying its dimensions: 3 ft × 2 ft × 4.5 ft, yielding 27 cubic feet. Since the specific gravity of the fluid is 0.85, and specific gravity is the ratio of the density of the fluid to the density of water, we can determine the weight of the fluid by multiplying the volume by the specific gravity and then by the weight of water per cubic foot (62.4 lbf/cu ft).
The weight of the fluid alone in the container is 27 cu ft × 0.85 × 62.4 lbf/cu ft = 1431.72 lbf. Adding the weight of the empty container, the total weight is 1431.72 lbf + 15 lbf = 1446.72 lbf. Work is calculated by multiplying the force needed to move the object by the distance over which the force is applied. Since we are pushing the container horizontally, we can use the weight as the force, resulting in 1446.72 lbf × 20 ft of work done. Converting this to kilojoules (× 0.00135582 kJ/ft.lb) gives us the final answer.
Total work done = (1446.72 lbf × 20 ft) × 0.00135582 kJ/ft.lb = 39.20 kJ.