cubic feet of liquid to gallons (US)

[jimk]

I have a well that is 240 feet deep and is 8 inches in diameter. How many gallons of water does it hold?

[Knight]

I have a well that is 240 feet deep and is 8 inches in diameter. How many gallons of water does it hold?

The Subject of your post shows that your on the right track, you know that we can calculate the volume of the well in cubic feet, We do this by determining the volume of a cylinder.

The formula for the area of a cylinder is the area of the circle times the depth, or ð * r² * h.

If the diameter is 8 inches, then the radius is 4 inches, 0r 0.333 feet.

Given:

ð * r² * h = volume

Then:

3.1415 * (0.333 Ft)² * 240 Ft = v Ft³

3.1415 * 0.11089 Ft² * 240 Ft = 83.87 Ft³

So there are 83.87 Ft³ of water in the well. I'm guessing that you've already gotten this far. What you seem to be looking for is the conversion of Cubic feet to gallons.

There are 7.481 gallons per cubic foot (http://www.convert-me.com/en/convert/volume), so:

83.87 Ft³ * 7.481 gal/Ft³ = 627.43 gallons