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Homework Help: Car Collision Problem - Halp!

  1. Feb 5, 2012 #1
    1. The problem statement, all variables and given/known data
    A red car with speed 30.0m/s and a blue car with speed 25.0m/s are initially 200m apart and heading toward each other on a one-liner road. The brakes on the red car can produce an acceleration of 3.40m/ss while the breaks on the blue car can produce an acceleration of 3.25m/ss.
    A) Do the cars collide? If yes, where?
    B) If they collide find speed of each car upon collision.

    2. Relevant equations
    I found out both cars' locations if the final velocity is 0, I also found where the time it takes each car to have a velocity of 0. The red car reaches v=0 at 132m and the blue car reaches v=0 at 103.8 m. So clearly they crash because 103.8 < 132. How do I find out WHERE they crash?

    3. The attempt at a solution
  2. jcsd
  3. Feb 5, 2012 #2
    Write down the distance each car goes as a function of time, X_r and X_b. You also know X_r + X_b = 200 (with a particular choice of coordinates for each car) at t = t_collision.
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