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Homework Help: Angled tension problem

  1. Oct 20, 2009 #1
    1. The problem statement, all variables and given/known data
    An object on an inclined ramp of mass 4 kg forms an angle of 34° with the horizontal. The object on the ramp is connected to a second object of mass 6.4 kg on a horizontal surface below an overhang that is formed by the inclined surface. An external force of 30 N is exerted on the object on the ramp. Both objects are accelerating. Assume that the surfaces and the pulley are frictionless, and the connecting string and the pulley are massless, what is the tension in the string connecting the two objects?

    2. Relevant equations

    F = ma
    m1g - T = m1a
    T - m2g = m2a

    3. The attempt at a solution

    I drew out the FBD for the object on the incline

    The force of gravity of the object must be broken into component parts:

    (4)(9.8) = 39.2 N
    x component: 39.2 sin34 = 21.9 N
    y component: 39.2 cos34

    The x component is counteracting the exerted force of 30 N, so 30-21.9 = 8.1 N

    object 2 is not on an incline so: (6.4)(9.8) = 62.7 N is the force applied on it

    8.1 - T = 4a
    T - 62.7 = 6.4a

    From here I am lost because if the above equations are solved for a - it turns out to be negative.

    Any help in finding acceleration and then tension would be greatly appreciated
    Last edited: Oct 20, 2009
  2. jcsd
  3. Oct 20, 2009 #2

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