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Homework Help: Tranlastion Motion

  1. Sep 13, 2007 #1
    1. The problem statement, all variables and given/known data
    A red train traveling at 72 km/h and a green train traveling at 144 km/h are headed toward one another along a straight, level track. When they are 950 km apart, each engineer sees the other's train and applies the brakes. The brakes decelerate each train at the rate of 1.0 m/s^2. Is there a collision? If so, what is the speed of each train at impact? If not, what is the separation between the trains when they stop?

    2. Relevant equations
    x=x0 + v0T + (1/2)(x - x0)

    3. The attempt at a solution
    I tried using the above equation, but I could not get a reasonable answer. I changed everything to meters and seconds. Here are the changes for those units:

    95 km = 950,000 m
    221 km/h = 61.39 m/s
  2. jcsd
  3. Sep 13, 2007 #2
    Just split it into two equations, and find the distance it takes to stop each one.
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