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Homework Help: Find acceleration

  1. Jan 20, 2015 #1
    1. The problem statement, all variables and given/known data
    A car is traveling at 95 km/hr. The driver steps on the brakes and the car comes to a stop in 60 meters. What is the car's acceleration?

    2. Relevant equations
    My issue might be which formula is correct but, I believe I would use, vf^2=vi^2+2ax

    3. The attempt at a solution
    Every time I begin any problem I write down the givens.
    d= 60 meters
    Vi= 95 km/hr
    Vf= 0 m/s
    Are my givens wrong? If not, I've continued to plug it in into the problem above. I assume I'm using Kinematics and since the other equations require 't' or time, I don't believe I use those equations for this problem. As I plug the givens into the equation above, the math doesn't add up to the answer my teacher had said it was; which is -5.81m/s^2.
  2. jcsd
  3. Jan 20, 2015 #2
    Would I have to convert the 95 km/hr?
  4. Jan 20, 2015 #3
    That is one of your first steps to convert it out to get similar units.
  5. Jan 20, 2015 #4
    Thank you! I got the answer now!! :D
  6. Jan 20, 2015 #5
    Happy to help :-)
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