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Homework Help: Braking system problem

  1. Nov 9, 2006 #1
    A car is traveling at 7 m/s when the wheels are locked up. The car slides 1.5 meters before coming to rest. If the car had been moving at 14 m/s, how far would the car slide, assuming the same breaking force is used?

    Not sure where to go with this problem...
     
  2. jcsd
  3. Nov 9, 2006 #2

    OlderDan

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    Hint: Which of the equations of motion relates initial velocity, final velocity, acceleration, and distance moved?
     
  4. Nov 9, 2006 #3
    I used the equation v^2=Vo^2+2(a)(S-So) and solved for acceleration, then plugged in new value for initial velocity and used the found acceleration. Is this correct?

    accel. = -16.3m/s^2
    distance traveled @ 14 m/s = 6.01 m
     
  5. Nov 9, 2006 #4

    OlderDan

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    Close enough, and that's exactly the correct approach. Since the velocity doubled, the stopping distance would be 2^2 = 4 times as great for the same acceleration.
     
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