# Cylindrical tank

• Feb 22nd 2010, 02:14 PM
Selim
Cylindrical tank
A vertical cylindrical tank of diameter 3 ft. and height 6 ft. is full of water (weighing 62.5 $\displaystyle lb/ft^3$ ).

Find the work required to pump the water out over the top of the tank. Leave $\displaystyle \pi$ in your answer!
• Feb 22nd 2010, 02:34 PM
Selim
Or would it be better to try it like this?

$\displaystyle \int(0 - y) * 3) * dV$ from -6 to 0

This comes out to 3375 inches-pounds from the diameter and the arbitrary cross section to for the height variable but then is mutiplied by $\displaystyle 13.5\pi.$

Can someone please check this? I don't feel at all good about it :(

And I'm not even sure if I accounted for three dimensions there?
• Feb 22nd 2010, 04:36 PM
skeeter
Quote:

Originally Posted by Selim
A vertical cylindrical tank of diameter 3 ft. and height 6 ft. is full of water (weighing 62.5 $\displaystyle lb/ft^3$ ).

Find the work required to pump the water out over the top of the tank. Leave $\displaystyle \pi$ in your answer!

$\displaystyle W = 62.5 \pi (1.5)^2 \int_0^6 (6-y) \, dy$