A satellite launch rocket has a cylindrical fuel tank. The fuel tank can hold V cubic meters of fuel. If the tank measures d meters across, what is the height of the tank in meters?
+128408 V = pi (d/2)^2 * h
V = pi (d^2 / 4) * h
h = 4V / ( pi * d^2) (meters)
+171 this is how you find the volume of a cylinder:
$V=\pi r^2h $
in our case, the thing is using the diameter instead of r, which is no big deal ; thus you can write it as : $\pi \left(\frac{1}{2}d\right)^2h=V$
we want to solve for h:
$\frac{\pi }{4}d^2h=V$
get rid of the fraction form:
$\pi hd^2=4V$
take pi d^2 to the other side:
$h=\frac{4V}{\pi d^2}$
and thats it!
