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Homework Help: Motion of two cars

  1. Dec 26, 2008 #1
    1. The problem statement, all variables and given/known data

    A ford is travelling at 59 km/h while a Holden has a speed of 60 km/h

    Calculate the velocity of the Holden relative to the Ford when they are travelling in:

    in the same direction

    3. The attempt at a solution

    59+60 = 119 km/h

    However the answer is 1 km/h.

    I don't understand why it's 60-59 km/h
  2. jcsd
  3. Dec 26, 2008 #2


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    Gold Member

    Have you drawn out this problem? It's pretty easy to figure out.
  4. Dec 26, 2008 #3
    there are two vectors 59 km/h and 60km/h
    and they're travelling in the same direction.
    Shouldn't you add the two vectors?
  5. Dec 26, 2008 #4


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    Gold Member

    If you want to know the velocity of the two cars relative to one another, what is the proper way to handle the vectors. Put it this way. If you were driving one car and looking at the the other car, what would you see the other car doing?
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