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Homework Help: Help, Motion with pulleys

  1. Feb 13, 2009 #1
    1. A pulley has a massless in extensible thread whose one side has a 5 kg block along with a spring of k=40 with it and the other end has a 2kg block (which is on the ground ). Find velocity of the 5kg block when the 2 kg block moves up.

    The Equations part :
    taking Tension as T , and extension cause by 5kg block as x1 and 2kg block as x2
    we have:

    That includes my attempt as well.
    I could find out the x1+x2 = 7/4 but then the velocity with that comes around as 3.45 m/s , but the correct answer is 1.414 m/s <2^1/2>.
    Last edited: Feb 13, 2009
  2. jcsd
  3. Feb 13, 2009 #2


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    You seem two have omitted sections two and three from the homework template.
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