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How the tension is calculated?

  1. Feb 28, 2014 #1
    A massless rod of length L attached to mass m and with axle to cart of mass M. The cart has a shape of equilateral triangle (edge L). the cart is at rest and its center of mass is above x=0 and a rod is perpendicular to the ground. the cart is free to move without friction. at time t=0 the mass m is released and starts to fall to the left. at time t=τ the rod is parallel to the ground. Why the tension from the stick at time t=τ is T=mv^2/L=2mg and not T=mv^2/L=mg?

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    Last edited: Feb 28, 2014
  2. jcsd
  3. Feb 28, 2014 #2


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    What do you think?
    Any relevant equations?
    Any ideas of you?
  4. Feb 28, 2014 #3
    mv^2/L is the radial force that need to be equated with the tension force....but the torque mgsin 90 = mg
    Last edited: Feb 28, 2014
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