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Homework Help: Accelerations without friction problem

  1. Oct 15, 2005 #1

    I seem to be having some problems solving this. First of all, I figured out what the acceleration of the blocks would be without friction. I'm not sure if this is correct or not but I found that a = 5.0 m/s/s. I did this by using
    Fp - Tension = ma and,
    T = ma.

    Then I factored in kinetic friction and I am getting ~.66 m/s/s using the same two equations except subtracting u*m*g from the left of each equation. That's not correct, is it? Going from 5 to less than 1 seems wrong to me.. Anyone know what I'm doing wrong?
  2. jcsd
  3. Oct 16, 2005 #2
    You sould find the force of friction because that's what pulling the block back. When 2 block are connected with strings, the tension in the string between the boxes wouldn't matter anymore. ust assume it as if it's one big chunk of block wwith mass of 30 kg.

    Then you find that Fp - Ff = ma

    You should get something about 0.687 m/s2
  4. Oct 16, 2005 #3
    Thank You

    I have been working on that problem for hours!!! Thank you!!!

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