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Homework Help: Size and direction of the change in velocity

  1. Sep 20, 2007 #1
    1. The problem statement, all variables and given/known data
    Find Size and direction of the change in velocity:

    a)5m/s west to 10 m/s west

    b)10m/s west to 5m/s west

    c)5m/s west to 10m/s east

    2. Relevant equations



    3. The attempt at a solution

    a)10-5= 5 west

    b)5-10=-5 because there isn't size wihe negitve the answer will be 5 to oppicite direction (east)

    C) My problem here the book says the answer will be 15 m/s east but I don't how it come up with it ?

    can you explain it for me ?
     
  2. jcsd
  3. Sep 20, 2007 #2
    5m/s west is equal to -5m/s east.
     
  4. Sep 21, 2007 #3
    Think you FedEx
    5m/s west to 10m/s east = 15 m/s east here my problem
    From where I can get 15? why does the book add them?even I know that if I want to know finall velocity v2-v1 but here v2+v1 why ????????
     
  5. Sep 21, 2007 #4
    (10m/s east) - (5 m/s west) = (10 m/s east) - (- 5m/s east) = 15 m/s east
     
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