Question

a water tank is in the form of a right circular cylinder with 20 ft and radius 6 ft. if the tank is half full of water, find the work required to pump all of its water over the rim?

Answer 1

\[R=6 ft , H=20 ft\]
\[A=mg(H-h_{cm})\]
m is whole water mass \[m=\rho\frac{\pi r^2H}{2}\]
\[h_{cm}\] is center of mass position \[h_{cm}=\frac{H}{4}\]
Now you will get \[A=\rho\frac{\pi r^2H}{2}g(H-H/4)=\frac{3\pi\rho gr^2H^2}{8}\]