An elevator's motor produces 3000 W power. The speed with which it can lift a 1000 kg load is:
Correct answer: C. 0.306 m s-1
- A. 30.6 ms-1
- B. 3.06 ms -1
- C. 0.306 m s-1
- D. 300.6 m s-1
Explanation
P = Fv P=mgv ⇨ v = P/mg = 3000/1000×10 = 0.306 ms-1
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
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.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Physics questions like this
Physics is on 16 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Work and Energy questions
An engine pumps up 100 kg of water through a height of 10 m in 5s. Given that the efficiency of the engine is 60%, what is the power of the engine? (Take g = 10 ms-2)
A mass hangs on a string fixed at point P. It starts from position 1 and swings to the furthest position on the opposite side, position 2. It then oscillates several times with decreasing amplitude before ending at position 3. Where does the ball have the most kinetic energy?
In the presence of air friction, the relation for free falling body is
The power needed to lift a mass of 5000g to height of 1 m in 2 second is?
An engine pulls a car of mass 1500 kg on a level road at a constant speed of 5 ms-1. If the frictional force is 500 N, what power does the engine generate?
When the applied force and covered displacement are parallel to each other than work done of the body is: