An engine pumps out 50 kg of water. If the water comes out vertically upwards with a velocity of 20 m/s. The power of the engine is (take g = 10 ms-2)
Correct answer: A. 10 KW
- A. 10 KW
- B. 20 kW
- C. 1000 W
- D. 10 MW
Explanation
To calculate the power of the engine, we can use the formula: Power = Force × Velocity First, let's find the force exerted by the engine to pump out the water. The force required to lift the water vertically upwards can be calculated using Newton's second law of motion Force = mass × acceleration Since the water is being lifted vertically upwards, the acceleration is equal to the acceleration due to gravity (g = 10 m/s^2). Force = 50 kg × 10 m/s^2 = 500 N Now, we have the force (500 N) and the velocity (20 m/s). We can calculate the power: Power = Force × Velocity Power = 500 N × 20 m/s = 10,000 N·m/s Since 1 N·m/s is equal to 1 Watt, the power of the engine is: Power = 10,000 Watts So, the power of the engine is 10,000 Watts.
Last updated
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.
Practise Work and Energy
748 free Work and Energy MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.