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Homework Help: Block on Wedge Problem

  1. Sep 21, 2006 #1
    A block of mass 'm' slides on a wedge of mass M. The wedge also moves on a smooth frictionless surface. Find the acceleration of the wedge.

    I have written down the equations of motion for the wedge and the block but dont know how to proceed further as there are more variables than equations:

    a= ax + ay (block)
    A = acceleration of wedge

    For block:

    [tex]Nsin\theta = m(ax)[/tex]
    [tex]Ncos\theta - mg = m(ay)[/tex]

    For wedge:
    B is the normal reaction by the ground on Wedge
    [tex] B = mg + Ncos\theta[/tex]

    What do I do after this? I think I have to work out a constraint relation here but I am not sure how to do it. Please help.
  2. jcsd
  3. Sep 21, 2006 #2

    Doc Al

    User Avatar

    Staff: Mentor

    First find the horizontal accelerations involved. What's the relationship between A and ax? Your constraint is that the block maintains contact with the wedge. (Hint: View things from the frame of the wedge.)
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