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Homework Help: Car crash collsion

  1. Apr 7, 2008 #1
    A 480kg car moving at 14.4m/s hits from behind another car moving at 13.3m/s in the same direction. If the second car has a mass of 570kg and a new speed of 17.9m/s what is the velocity of the first car after collision?

    Since there is a velocity for one car after the collision and the question asks for the other car's velocity after the collison this collision must be elastic.
    m1v1 + m2v2 = m1v1f + m2v2f
    480*14.4 + 570*13.3 = 480v1f + 570*17.9
    14493N = 480v1f + 10203N
    4290N = 480v1f
    8.94m/s = v1f

    Is this right?
  2. jcsd
  3. Apr 7, 2008 #2
    Looks right to me.
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