SOLUTION: I am trying to find the radius of a propane tank, with the shape of a cylinder with hemishperes on the ends. Total volume is 791.28 cu ft and Cylinder part length of the tank

Algebra ->  Volume -> SOLUTION: I am trying to find the radius of a propane tank, with the shape of a cylinder with hemishperes on the ends. Total volume is 791.28 cu ft and Cylinder part length of the tank       Log On


   



Question 702539: I am trying to find the radius of a propane tank, with the shape of a cylinder with hemishperes on the ends.
Total volume is 791.28 cu ft and
Cylinder part length of the tank is 10 ft.
I started with:
pi*r^2*h + pi*r^3*4/3 = V
:
pi/3 * (3r^2*10 + 4r^3) = 791.28
:
30r^2 + 4r^3 = 791.28*3/pi
:
r^2 * (30+4r) = 756 (using pi=3.14)
:
I am stuck at how to solve for "r"
thanks in advance,

Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


Use an on-line calculator for cubic equations.

Solve it as

It is a bit more than 4 ft. 4.045 to three places.

John

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My calculator said it, I believe it, that settles it
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