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Homework Help: Finding angular velocity based on x vs t graph

  1. Dec 10, 2009 #1
    1. The problem statement, all variables and given/known data

    I am given the attached graph (excuse my abysmal homemade graph!). On the y-axis, I presume that it is displacement (x). The x-axis is time. This graph looks like SHM, but I could be wrong! The graph rises from 0 to 2 every 2 seconds, and drops back to 0 on the y-axis for 2 seconds before repeating the cycle. The problem asks to find angular velocity based on the graph. I am given the choices of 2.0 rad/s, 0.5 rad/s, 1 rad/sec, or none of above.



    2. Relevant equations

    This graph looks like SHM, but I could be wrong!


    3. The attempt at a solution

    I really have no clue how to derive angular velocity based on this graph. I am guessing you have to find tangential velocity from the graph and from there determine angular velocity using the formula v(tangential) = ω r. Am I on the right track? Again, please excuse the poor graph. :)
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     

    Attached Files:

  2. jcsd
  3. Dec 11, 2009 #2
    That graph can't be a x(t) plot because of the verticle segments. This says that somhow a particle covered some distance x in zero time. Also the velocity is undefined at those points. If you were just looking at it on a cycle or periodic basis then you would say it completes 1 cycle in 4s. And in one cycle there are 6.28rads. So you would get 1.57rad/s which would be none of the above.
     
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