Power to life a piano question

AI Thread Summary
To lift a 200 kg piano to a height of 20 m using a 0.5 hp motor, the motor must perform work against gravity, which can be calculated using the formula for gravitational potential energy. Since 1 hp equals 746 watts, the motor provides 373 watts of power. The energy required to lift the piano is 3,920 joules, calculated from the formula E = mgh (mass x gravity x height). With the power output of the motor, the time taken to lift the piano can be determined by dividing the energy by the power. Understanding the relationship between watts, joules, and time is crucial for solving this problem effectively.
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Power to lift* a piano

A piano of mass 200 kg is lifted vertically by a 0.5 hp motor. Given that 746 watt = 1 hp,
how long will it take the motor to lift the piano to an apartment that is 20 m above the
ground?

Not really sure how to start this question, so any explanation would be greatly appreciated.
 
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1 watt = 1 joule of energy / 1 second

And has you lift the piano you are doing work ( in Joules ) to raise the piano against the Earth's gravity so now you have a connection between time ( what you are looking for ) and the energy involved in lifting the piano.

A free body diagram might help you as well to visualize. (i.e. draw a picture including ALL of the forces acting on the piano). Have fun!
 
ooh ok, I didn't realize that 1 watt = 1 joule per second, that helped out quite a bit. Thanks so much for the response!
 
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