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Exam tom. need help on this question

  1. Oct 19, 2003 #1


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    a 3.00kg block starts from rest at the top of 30.0 degree incline and slides 2.00m down the incline in 1.50s find:

    a). acceleration of the block
    b). coefficent of kinetic friction between the block and the incline
    c). frictonal force acting on the block
    d? the speed of the block after it has slid 2.00m
  2. jcsd
  3. Oct 19, 2003 #2
    what have you got so far, and where are you stuck?
  4. Oct 19, 2003 #3


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    i have no idea how to do this kind of question. I am very confused
    Last edited by a moderator: Oct 19, 2003
  5. Oct 19, 2003 #4
    What I do is, first of all write down all of the information given in the question:

    u = 0 m/s
    v = v
    a = a
    s = 2.00 m
    t = 1.50 s

    mass=3.00 Kg

    a) Use the formula: s = ut + 0.5 a t^2

    b) Since the block is sliding, F = [mu] R
    Therefore [mu]=Tan30

    c) Since F = [mu] R
    F = Tan30 * 3.00*9.81*Cos30

    d) Using the u, v, a, s, t that I wrote down before, substitute values into this equation:

    v = u + a t

    Hint: For this type of question, I highly recommend drawing a diagram with all the information on at the very start of the question before you do anything else, it will help you to visualize the question and also contains key information that you can remind yourself of at a quick glance.
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