SOLUTION: a cylindrical chemical storage tank must have a height 4 meters greater than the radius of the top of the tank. Determine the radius of the top and the height of the tank if the ta

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Question 346274: a cylindrical chemical storage tank must have a height 4 meters greater than the radius of the top of the tank. Determine the radius of the top and the height of the tank if the tank must have a volume of 15.71 cubic meters.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
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a cylindrical chemical storage tank must have a height 4 meters greater than
the radius of the top of the tank.
Determine the radius of the top and the height of the tank if the tank must
have a volume of 15.71 cubic meters.
:
Let r = the radius of the tank
It says,"must have a height 4 meters greater than the radius." therefore
(r+4) = the height of the tank
:
Volume of a cylinder: V = pi%2Ar%5E2%2Ah
Therefore
pi%2Ar%5E2%2A%28r%2B4%29 = 15.71
divide both sides by pi, results
r^2(r+4) = 15.71%2Fpi
r^3 + 4r^2 = 5
r^3 + 4r^2 - 5 = 0
just from looking at this you know that r=1, then the height = 5
:
:
Check this
V = pi%2A1%5E2%2A%281%2B4%29
v = 15.707 ~15.71