Question 1151345
A hollow steel tube is 30 ft. in length, 18 in. in diameter.  Determine volume.

Volume = pi * height * (R^2 - r^2)  R = larger radius  r = smaller radius

V = 3.1416 * 30 * .75 * .75 * r   smaller radius not given.

V = 53.0145 cu. ft.

Not sure of my calculations.
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Vol = pi*30*(0.75^2 - r^2) cubic feet
= 30pi*(0.5625 - r^2) cf --- r < 0.75
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You can't get a number without knowing r
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If you ignore the wall thickness,
Vol = pi*30*0.75^2 cubic feet = the number you have.