An electric water pump rated 1.5 kilowatt lifts 200kg of water through a vertical height of 6meter in 10seconds what is the efficiency of the pump

Answer 1

energy = m g h = 200 kg * 9.8 m/s^2 * 6 m = ? Joules

power = work / time = energy / 10 s = ? Watts

efficiency = power / 1.5 kw

Answer 2

F = M*g = 200*6 = 1200 N.
Po = F*d/T = 1200*6/10 = 720 J/s = 720 Watts = power out.
eff. = (Po/Pi) * 100% = (720/1500) * 100% = 48%.