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Homework Help: Relative velocity - two cars

  1. Oct 9, 2008 #1
    1. The problem statement, all variables and given/known data
    how long does it take a car traveling in the left lane at 60 km/h to overtake another car traveling in the right lane at 40 kn/h when the cars front bumpers are initially 100 m apart?

    2. Relevant equations
    relative velocity equations
    V ab = v ae + V be

    3. The attempt at a solution
    i dont really know my work doesnt make sense and theres no sense typing it all in here cause its wrong and i cant even get al the symbols
  2. jcsd
  3. Oct 9, 2008 #2
    Relative to the 40km/h car, the car in the left lane is travelling 20km/h.

    So now you have relative velocity, they give you relative distance (100m) solve for time.

    velocity = distance / time

    Hint #2:
    Don't forget to convert relative velocity to m/s if you want it in si units.
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