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Homework Help: Finding Acceleration

  1. Mar 19, 2010 #1
    1. The problem statement, all variables and given/known data

    A motorist enters a freeway at 45km/h and accelerates uniformly to 99 km/h. From the odometer of the car, the driver knows she has travelled 0.2km. Find the acceleration of the car.

    2. Relevant equations



    3. The attempt at a solution

    I attempted this:

    v2 = u2 + 2as

    Substituting the values in I got this:
    (992 -452)/0.4 = a

    this gives 19440, so converting to m/sec I think I get 5400 m/sec2

    This is definitely not right, any ideas why?

    Cheers,
    Adrian :)
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Mar 19, 2010 #2

    Doc Al

    User Avatar

    Staff: Mentor

    What units do you think the 19440 would be in? Check your conversion.

    The best thing to do is change units to m/s and m before you use them in the formula.
     
  4. Mar 19, 2010 #3
    Got it! Thanks a bunch!

    Cheers,
    Adrian
     
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