Question

"A tank is full of water. Find the work required to pump the water out of the spout. (Use 9.8 m/s2 for g. Use 1000 kg/m3 as the density of water. Assume r = 3 m and h = 1 m.)
"

Answer 1

Distance = 3+1 = 4 m
Weight of water = 9.8*Pi*9^3*1000*4/3
                          = 29.926*10^6 N 
Work done = 4 * 29.926 * 10^6
                  = 119.70 × 10^6 J
                  = 119.70 MJ.