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Homework Help: Finding the mass of a block on an incline attached to a pulley!

  1. Sep 16, 2010 #1
    1. The problem statement, all variables and given/known data
    The two mass system shown below has the same coefficient of kinetic friction on both the horizontal and inclined surfaces. When the system released from rest, both blocks quickly reach a constant acceleration of 2.00 m/s^2. M2=5.00 kg (on horizontal. Find the mass M1 of the block on the incline. Please see attached picture!!

    2. Relevant equations
    Newtons second law

    3. The attempt at a solution Im super stuck :( i tried to start working with newtons equation but i hit a dead end! can someone help set me up pretty please :) with a cherry! ive spent and hour on this!

    Attached Files:

    Last edited: Sep 16, 2010
  2. jcsd
  3. Sep 17, 2010 #2
    Use Newtons laws applied on each block and solve the system of equations. The easiest way would be to solve for the tension in the rope given the information for the 5kg mass...
  4. Sep 17, 2010 #3
    Hmm okay my friend and i are both stuck on this one!
    How could i solve for the tension? im trying to set up vectors its just not clicking for me
  5. Sep 17, 2010 #4
    Can i do this. A=(F-f)/m to solve for the force?!
  6. Sep 17, 2010 #5
    Newtons laws on the top block yield:
    T-f=(5kg)(2 m/s^2)
    you can calculate friction 'f' so the only unknown is tension 'T'.
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