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Homework Help: Mechanics question

  1. Jun 3, 2010 #1
    1. The problem statement, all variables and given/known data

    Car X moves with a constant speed of v m/s on a straight road heading towards a stationary car Y on the road. When car X is b m behind car Y, car Y starts to move with a uniform acceleration of a m/s^2 in the same direction as the direction of car X until it achieves a constant speed of v m/s . If car X did not overtake car Y, show that v<root(2ab)

    2. Relevant equations



    3. The attempt at a solution

    I need to get started.
     
  2. jcsd
  3. Jun 3, 2010 #2
    Hint; use the equation v2 = u2 + 2 * a * s

    where u = initial velocity and s = displacement
     
  4. Jun 3, 2010 #3
    ok ,

    so for car Y , usign

    v^2=u^2+2as

    v^2=2ab

    v=root(2ab) and this is the final speed of car y

    And car X did not overtake car Y , so Vy>Vx

    root(2ab)>v

    Is it that simple? This question has 5 marks . Thanks anyways .
     
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