JEE Main Physics question
A cubical vessel of height 1 m is full of water. What is the amount of work done in pumping water out of the vessel? (Take g = 10 ms⁻²)
Answer: (B)
Solution
Volume = 1³ = 1 m³, mass m = 1000 kg; the centre of mass of the water is at height 0.5 m. Work done = mg(h/2) = 1000×10×0.5 = 5000 J.