Power of a water pump is 2 kW. If g=10m/sec2, the amount of water it can raise in one minute to a height of 10m is
Correct answer: C. 1200 litre
- A. 2000 litre
- B. 1000 litre
- C. 1200 litre
- D. 100 litre
Explanation
The explanation of this question is: Power (P) is defined as the rate at which work is done, and it is measured in watts (W). In this case, the power of the water pump is given as 2 kW, which is equal to 2000 watts. The work done by the pump can be calculated using the formula: Work (W) = Power (P) × Time (t) We know the power (P) is 2000 watts, and the time (t) required to raise the water to a height of 10 meters is 1 minute or 60 seconds. Work (W) = 2000 W × 60 sec m = mass of the object (in kg)g = acceleration due to gravity (in m/s²)h = height (in meters) In this case, the height (h) is 10 meters, and the acceleration due to gravity (g) is 10 m/s². To raise the water, work is done against gravity, therefore Potential Energy is gained. W = PE = mgh mgh = Pt m = 2000 x 60/10 x 10 m = 1200 kg Now density of water = ρ = 1 kg/l ρ = m/v 1000 = 1200/v V = 1200/1 = 1200 litres.
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About Work and Energy
Work transfers energy when a force causes displacement, while kinetic energy, gravitational potential energy and power describe motion, position and the rate of energy transfer. The work-energy theorem links net work with change in kinetic energy, and efficiency accounts for energy losses rather than treating them as energy destruction.
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