Question

8. In rural third world countries, farmers use a

conical bucket, the "Gầu Dây” to drain/transfer
water from one rice field to another. If the height
is 20" & the diameter of the opening is 15”, how
much cubic feet of water can two farmers drain
in three hours if their rate is 28 “gầu" per
minute?

Answer 1

9514 1404 393

Answer:

6872 cubic feet

Explanation:

The volume of the conical bucket is ...

V = 1/3πr²h

V = 1/3π(15/2 in)²(20 in) = 375π in³

There are 60 minutes in 1 hour, so 3×60 = 180 minutes in 3 hours.

If each of 2 farmers can transfer 28 buckets per minute the total amount transferred is ...

(375π in³)(180 min)(2 farmers)(28/min/farmer) = 3,780,000π in³

There are 1728 in³ in 1 ft³, so this is ...

(3,780,000π/1728) ft³ = 2187.5π ft³, about 6872 cubic feet.