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Super ball Motion problem

  1. Sep 5, 2008 #1
    1. The problem statement, all variables and given/known data

    A 50.0 g Super Ball traveling at 30.0 m/s bounces off a brick wall and rebounds at 22.0 m/s. A high-speed camera records this event. If the ball is in contact with the wall for 5.00 ms, what is the magnitude of the average acceleration of the ball during this time interval? (Note: 1 ms = 10-3 s.)

    2. Relevant equations

    avg acceleration=(final V-initial V)/change in time

    3. The attempt at a solution

    (22m/s-30m/s)/0.005s= -1600m/s^2 and since it asks for the magnitude my final answer is

    This was from my online physics homework. I really don't see what i'm doing wrong.
  2. jcsd
  3. Sep 5, 2008 #2


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    Homework Helper

    I think you need to look at your direction signs more carefully.

    Remember velocity is a vector. The sign you assign it needs to be carried through the calculation.
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