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Average power input

  • Thread starter lzh
  • Start date
  • #1
lzh
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Homework Statement


A wheel with rotational inertia I is mounted on a fixed motionless axle. The singular speed w of the wheel is increased from 0 to Wf in a time interval T.
Net torque=IWf/T

What is the average power input to the wheel during this time interval?

Homework Equations


P=torque*angular velocity


The Attempt at a Solution


P=(IWf/T)*Wf=(IWf^2/T)
This isn't right though, what am I doing wrong?
 

Answers and Replies

  • #2
diazona
Homework Helper
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Think about this: what's the power input at t = 0? Or at t = T/2? Or generally, at any time between 0 and T? You only calculated the power input at one particular time, but the problem asks for the average.
 
  • #3
lzh
111
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I was thinking of finding the integral of the power from 0 to T and then divide everything by T. But for some reason the answer is coming out weird.
 

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