An empty spherical water tank with a radius of 8 m has its lowest point 2 m above the ground. A pump is used to move water from a source on the ground into the tank. 

a. How much work is done by the pump to fill the tank if all the water is pumped into the tank through an inflow pipe that runs from the water source to the bottom of the tank (see figure)? 

b. Assume instead that the water is pumped from the ground through an inflow pipe that leads to the top of the tank. How much work is done by the pump to fill the tank? (Ignore the work done by gravity to drain the water into the tank.)

Transcribed Image Text:

8 m 2 m inflow pipe