Answer:
The muscular work completed by four men will be 2400 ft. lbs.
Step-by-step explanation:
See the diagram of the ramp.
Four men carry 20 boxes each up a ramp as shown.
So, 4 men carry total (4 × 20) = 80 boxes up the ramp and each box weighs 5 pounds.
Then, the 4 men carry total (80 × 5) = 400 lb weight up the ramp.
Now, the vertical height of the ramp from the ground level is 6 ft.
Hence, the muscular work completed by four men will be (400 × 6) = 2400 ft. lbs. (Answer)
