Question 421907
A cylinder has a volume of 75,400 cubic feet.
 What is the radius of the cylinder if the height of the cylinder is 3 times longer than the radius?
:
Vol of cylinder: {{{V = pi*r^2*h}}}
:
Let x = the radius (r)
then
3x = the height (h)
:
{{{pi*x^2*3x}}} = 75400
{{{pi*3x^3}}} = 75400
Divide both sides by 3pi, results
x^3 = {{{75400/(3*pi)}}}
x^3 = 8000.2
x = {{{3sqrt(8000.2)}}}
x = 20.0 ft is the radius
:
:
:
Check solution on calc: enter: {{{pi*20^2*60}}} results: 75398.2237 ~ 75400