Math CentralQuandaries & Queries


Question from Nadine:

I have a pile of wheat in the shape of a cone. I would like to know how much wheat I have. I have found the equation "V=1/3 pie r squared h" , but it dosn't work! The pile is 7 feet high, diameter is 50 feet, circumference is 185 feet. I also measured the slope 19feet. (Probably not needed) You need to know that wheat weighs 60 pounds per bushel, and I would like to know how many bushels
I have. Even if I could receive the # of Volume Bushels, I could convert that.
Can you help me??

Hi Nadine. 

When you say the equation "doesn't work" what do you mean?  Here is how I would calculate it:

Diameter is 50 feet, so radius is 25 feet.
Height is 7 feet.
V = (1/3) π (252) (7) = 4581 cubic feet.

A volume bushel is 1.25 cubic feet, so this is 4581 / 1.25 = 3665 vol bu.

Here are a few useful references for grain bushels:

Stephen La Rocque
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