1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Virtual work problem

  1. Oct 16, 2011 #1
    See the diagram: [​IMG]
    The diagram is an ideal mechanical system of massless beams. The platform C holds a weight of "W". There are gear-motor mechanisms at connections A and B, which provide internal torques.

    Suppose, the smaller (acute) angle between beam OA and horizontal is θ.
    The mechanism at A provides an initernal torque to maintain the smaller angle BAO = 2θ.
    The mechanism at B provides an initernal torque to maintain the smaller angle ABC = 3θ.

    Using principle of virtual work (δU=0), find the minimum moment M which must be applied at O to raise the load W.

    Please help in solving the above problem. I cannot find a way to calculate the virtual work done by W when the virtual work done by M is Mδθ. Also what will happen to the internal torques provided. Will they appear in the moment M expression?

    Thanks for the help.
    Last edited: Oct 16, 2011
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?