posted by zahra .
Suppose you have a perfectly spherical water tank with an inside diameter of 8.6 metres. If the drain at the bottom of the tank can't handle a hydrostatic pressure of more than 50 kilopascals, what is the maximum volume of water, in litres, that can be contained in the tank? Assume that gravitational acceleration is exactly 9.81 m/s2.
Height of water makes the pressure. So solve for height.
Now, solve for H. That would be the height of mercury in the tank, but the tank holds water, so multiply H by 13.2. Now you have the depth of the water, use geometry (or calculus) to find the volume.
The author probably had a different technique in mind..