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Homework Help: Acceleration at the center of circle

  1. Feb 6, 2010 #1
    1. The problem statement, all variables and given/known data
    A circle with radius 2 cm rotates at 1000 rpm and the acceleration at the rim is 2 ms-2.
    a. What is the acceleration at the center ?
    b. What is the acceleration at 1 cm from the center ?

    2. Relevant equations

    3. The attempt at a solution
    a. The acceleration will be zero because the center doesn't move?

    b. a = ω2r = 2πf*r = 2π * 1000/60 * 2 x 10-2 = 2/3 π ms-2. Is this right?

  2. jcsd
  3. Feb 6, 2010 #2
    Your answer for a seems to be right. The problem is that the acceleration at the rim of a circle with radius 2 cm that rotates with 1000 rpm is more than 100 times as high as [itex] 2 m s^{-2} [/itex]
    I don't see why the acceleration is given at all in the problem.

    For part b you use [itex] \omega [/itex] instead of [itex] \omega^2 [/itex] and a radius of 2 cm instead of 1 cm
  4. Feb 6, 2010 #3
    Hi willem

    Yeah, my mistake...now I know it's not a good idea to post question at 2 AM..

    I also agree that the information given doesn't match the theoretical calculation...something wrong with the question...

    Thanks a lot !!
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