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Homework Help: 2 masses 1 on incline

  1. Mar 2, 2010 #1
    1. The problem statement, all variables and given/known data
    A mass m2 = 1.1 kg, on a 35.0° incline, is connected to a mass m1 = 6.0 kg, on a horizontal surface. The surfaces and the pulley are frictionless. If F = 17.5 N, what is the magnitude of the tension in the connecting cord?
    http://img717.imageshack.us/img717/1943/hmwork1.gif [Broken]

    2. Relevant equations

    3. The attempt at a solution
    Realy stumped on this one, i drew free body diagrams for each of the objects and attempted to eliminate the forces, i believe that F-(tension+m*g*cos(35)) = net force. Then i add the masses together and devide by M to get acceleration, and then plug acceleration back into f=ma but instead of the total mass i use 1.1 for m2.
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Mar 2, 2010 #2


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    Homework Helper

    Hi juggalomike, welcome to PF.
    F-(tension+m*g*cos(35)) = net force
    This step should be
    F-(tension+m*g*sin(35)) = m2*a ......(1)
    Next T = m1*a...(2)
    Solve these two equation to find a and T.
  4. Feb 15, 2012 #3
    i dont understand what mgsin is... are you talking about m1 or m2? help i am trying to figure this problem out and i still dont get it...
  5. Feb 15, 2012 #4
    mgsinθ is the resultant of normal force and gravity on the mass on the ramp.
  6. Feb 15, 2012 #5
    i still get it wrong.. i dont understand how to get "a" when tension is in the eq.... F-(tension+m*g*sin(35)) = m2*a ......(1) :( helppp
  7. Feb 15, 2012 #6
    You can us [itex]ma[/itex] in place of tension. Both objects will be accelerating at the same rate, so both a's will be the same. You now only have 1 variable, and can solve for acceleration.
  8. Feb 15, 2012 #7
    thank you for trying it seems i am doing something wrong bc it tells me its wrong. :(
  9. Feb 15, 2012 #8
    Well, tell us the answer, tell us what you are getting and show your work. I'm sure that we can help you figure out what you are doing wrong.
  10. Feb 15, 2012 #9
    wait! i was doing a silly mistake!! i got it! thank you thank you thank you!!! :)
  11. Oct 7, 2012 #10
    I still don't understand how to solve this problem.. please explain?
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