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Homework Help: Force of three boxes

  1. Sep 27, 2004 #1
    Three blocks of mass 12.5 kg each, on a frictionless horizontal surface are in contact with each other as shown in the figure below.

    A force F = 91.4 N is applied to block 1 (mass m1). Determine the acceleration of the system (in terms of m1, m2, and m3).

    I did 91.4 = 12.5a
    91.4/12.5 = 7.312 but something is missing to that equation. how do I do it in terms of m1, m2, and m3)?

    Attached Files:

  2. jcsd
  3. Sep 27, 2004 #2


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    Science Advisor
    Homework Helper

    Since all three blocks are in contact you are attempting to accelerate all three of them - i.e. the combined mass.
  4. Sep 27, 2004 #3
    That was an obvious answer that I should've gotten, thank you.

    Could you give me a pointer on this one too, having to do with the same problem?
    Calculate the force of contact that block m1 exerts on m2.
  5. Sep 27, 2004 #4

    Doc Al

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    Staff: Mentor

    Apply Newton's 2nd law to block m1 alone.
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