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Homework Help: Velocity,time,acceleration question

  1. Apr 17, 2009 #1
    A blue car moving at constant speed of 10m/s passes a polic car that is at rest. The police car accelerates from rest at 4m/s^2 for 3.0 seconds and then maintains a constant speed. The blue car maintains constant speed for the entire 12 seconds. When does the police car pass the blue car?

    Blue Car:
    Vi= 10 m/s
    Vf = 10 m/s
    deltaT = 12 s
    deltaD = 120 m
    acceleration = 0

    Police Car:
    Vi = 0m/s
    acceleration = 4m/s^2 (for the first 3 seconds)
    deltaD (for first three seconds) = 18 m
    Vf = 12 m/s

    So when the deltaD of the blue car = the deltaD of the police car, the police car is at the same distance as the blue car.

    How would I go about doing this?
  2. jcsd
  3. Apr 17, 2009 #2


    User Avatar
    Science Advisor
    Homework Helper

    Note how this problem is similar to this question.
    Probably if you solve the other one, you will be able to do this one yourself.
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