Weight of Water on Acre

[Guest]

I found this in an agricultural reference guide:

An inch of rain falls on an acre of land. Determine weight of water. ( I just reworded the statement into a problem).

A gal. of water weighs 8.5 lbs. A cu. ft. of water = 7.5 gal. and weighs 62.5 lbs.

The answer is given. How do I proceed ?

[Guest]

Using your US conversions......

A cubic foot of water 1 inch deep and 1 foot wide will be 12 feet long.

1 acre is 43560 square feet.

Imagine the acre is a rectangle 12 feet wide then every foot run has 1 cubic foot of water on it. OR every 12 square foot of area carries 1 cubic foot of water.

So find how many "12 square feet" there are in an acre....this will equal the number of cubic feet of water on an acre.

43560/12 = 3630 cu ft of water

Weight = 3630 x 62.5 = 226875 lbs of water on 1 acre at 1 inch deep.

Taking 2240 lbs in 1 ton gives 101.3 tons...........

[Guest]

Thanks.

According to the guide, the answer is 100 tons (just a general estimate).

226875 / 2000 = 113.4375 = 113 tons.