16 / Ricardo uses a chain hoist to lift a 645-pound air compressor 4.5 feet. Ricardo has to pull 54 feet of chain through the chain hoist. If the hoist is 95% efficient, how much force does Ricardo have to apply to the chain?

Let F be the force applied by Ricardo

work done by him = force x displacement

= F x 54 unit

output of work

= mgh, m is mass of luggage, h is height by which luggage is lifted.

= 645 x 32 x 4.5

= 92880 ft-poundal.

According to question

output / input =.95

92880 / (F x 54) =.95

F = 1810.52 poundal.