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Wind Turbine Question

  1. Nov 20, 2014 #1
    1. The problem statement, all variables and given/known data

    During a sustained wind the blades on a two blade horizontal–axis wind turbine is
    turning with an angular velocity of 5 rad/s. If initially the blades have an angular velocity of 2
    rad/s, determine the distance point P on the tip of the blade has travelled in 3.0 seconds. Also,
    what is the magnitude of the acceleration of this point when t = 3.0 seconds.

    Point P is the Tip of the blade. Radius is 4.55m.

    2. Relevant equations

    where w=omega (angular velocity in rad/s)



    3. The attempt at a solution

    Initially we have 2rad/s


    2rad/s * 4.55m=9.1 m/s

    5rad/s *4.55m= 22.75m/s

    I don't understand how to answer the question considering there is no information given on how fast it accelerates to 5rad/s. Does it instantly go to 5rad/s

    Any insight?
  2. jcsd
  3. Nov 20, 2014 #2


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    Gold Member

    It's not well worded but I think you are supposed to take the 5 m/s as the limiting speed as the duration of the sustained stronger wind tends to infinity. If so, you need to reason out how the angular velocity will increase with time. It will not be constant acceleration. Any ideas?
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