A petrol engine raises 200 litres of water in a well from a depth of 7 m in 6 seconds. Show that the power of the engine is about 2330 W.
Power = Work/Time
Work = Force x Distance
Force = Mass x Acceleration
Mass = Volume x Density
Volume = 200 litres
Density of water = 1000 kg/m^3
Distance = 7 m
Time = 6 seconds
Work = (200 x 1000 x 7) Nm
Work = 1.4 x 10^6 Nm
Power = 1.4 x 10^6 Nm/6 s
Power = 2.3 x 10^5 W
Power = 2330 W