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Pulley and ramp problem

  1. Sep 24, 2012 #1
    1. The problem statement, all variables and given/known data

    A mass [itex]m{1}[/itex] = 5kg is on a frictionless ramp and connected to a cable that passes over a pulley which is then attached to a second hanging mass, [itex]m{2}[/itex] = 10kg. How long will it take the boxes to move 3m if they are released from rest?

    [itex]F{A}[/itex]= Forces acting on hanging object
    [itex]F{B}[/itex]= Forces acting on object on ramp

    x57c4y.jpg

    2. Relevant equations

    F=ma

    3. The attempt at a solution

    I have solved for T using the force equation on object A and got T= -m1a + 98N

    Then I substituted for T in the equation for object B and solved for acceleration, yielding:


    a=(98N-49sin[itex]\vartheta[/itex])/15

    My biggest problem is, the book says the answer is 1.13 seconds. How can I solve in terms of seconds without another variable provided? I can't think of a way to use elimination to solve for [itex]\vartheta[/itex].
     
  2. jcsd
  3. Sep 24, 2012 #2

    Simon Bridge

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    The image didn't come out.

    But as to your question - assuming your are given the ramp angle - hint: kinematic equations.
     
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