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Homework Help: Finding acceleration with circular motion

  1. Sep 30, 2014 #1
    1. The problem statement, all variables and given/known data
    Entrance and exit ramps for freeways are often circular stretches of road. As you go around one at a constant speed, you will experience a constant acceleration. Suppose you drive through an entrance ramp at a modest speed and your acceleration is 2.0 m/s2.

    What will be the acceleration if you triple your speed?

    Express your answer to two significant figures and include the appropriate units.

    2. Relevant equations
    a = v2/R

    3. The attempt at a solution
    Given that the initial acceleration is 2.0 m/s2, and a = v2/R...

    I am not sure where to get started. R is not given, and v is not given. I know how to find a theoretically, but since I do not have concrete values to start with besides acceleration, I do not know where to begin.

    Thanks for any guidance.
  2. jcsd
  3. Sep 30, 2014 #2
    Try this with R = 50 m, and with whatever velocity you need to give you a = 2 m/s2. Now, if you triple v, what do you get for a?

  4. Sep 30, 2014 #3
    You don't actually need any more information, as you wrote yourself in a circular motion a = v2/R. now imagine, R is constant (because you are in the same road), you triple the speed, what will happen to acceleration?
  5. Sep 30, 2014 #4
    OK, I got it. Thanks all for your help!
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