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Power question

  • #1
I have a 300 kg piano being lifted at a steady speed from the ground to a hieght of 10 meters and the crane that is doing the lifting is providing 400 watts of power. How much time does it take to get the piano to the top.
So far I have Power = work/Time
so time is Work/ power , so, work is equal to mass X gravity X hieght
so I have (300)(9.8)(10)/(400) = 73.5 sec....is this correct....any help would be nice. Thanks
 

Answers and Replies

  • #2
Diane_
Homework Helper
390
0
For the information you have, it looks fine, although you'll want to check the significant digits.

It is, of course, an underestimate - do you see why?
 

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