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Power to life a piano question

  1. May 5, 2012 #1
    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.
     
    Last edited: May 5, 2012
  2. jcsd
  3. May 5, 2012 #2
    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!
     
  4. May 5, 2012 #3
    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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