A water pump extracts water from a depth 10 m below the ground. The water is pumped up at a rate of 30 kg/minute with negligible velocity. Determine the minimum horsepower the engine must possess to accomplish this.

Step-by-step solution

The work done by the pump in lifting water is equal to the change in potential energy of the water. Given: Mass of water pumped per minute, m = 30 kg Time, t = 1 minute = 60 s Depth, h = 10 m Acceleration due to gravity, g = 9.8 m/s ^2 The power required in watts is given by: P = mgh t Substituting the given values: P = 30 9.8 10 60 = 49 W To convert the power into horsepower, we use the conversion 1 hp = 746 W . P = 49 746 hp 0.066 hp