JEE Main Physics question
10 L of water per second is lifted from a well through 20 m and delivered with a velocity of 10 ms⁻¹, then the power of the motor is
Answer: (B)
Solution
Mass flow rate = 10 kg/s. Power = [mgh + ½mv²]/t (per second) = 10×10×20 + ½×10×10² = 2000 + 500 = 2500 W = 2.5 kW.