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Homework Help: Ramp Problem Help Needed!

  1. Oct 8, 2012 #1
    A block of mass 0.6 kg rests on the inclined
    surface of a wedge of mass 1.8 kg. The wedge
    is acted upon by a horizontal force F and slides on a frictionless surface.
    The acceleration of gravity is 9.81 m/s

    If the coefficient of static friction between
    the wedge and the block is 1 and the angle of
    the incline is 23º, find the minimum value of
    F for which the block does not slip.
    Answer in units of N

    My attempt to a solution

    I haven't done it b my plan is to find the normal force and friction to find the acceleration, but I noticed that in order for block to be still, mgcosθ should be equal to N and since the friction f = μN and μ=1, f = N so f = mgcosθ. It can't be right because f = Nsinθ and it just doesn't seem right. What should I do? Are there any mistake in my plan to solve this problem?
  2. jcsd
  3. Oct 8, 2012 #2


    User Avatar
    Homework Helper

    You need to take into account that a force is accelerating the wedge and the block.
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