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Homework Help: Constant Acceleration Car

  1. Jan 13, 2008 #1
    [SOLVED] Constant Acceleration

    1. The problem statement, all variables and given/known data
    a. What constant acceleration, in SI units, must a car have to go from zero to 60 mph in 10s?

    b. What fraction of g is this?

    c. How far has the car traveled when it reaches 60 mph? Give your answer both in SI units and in feet.


    2. Relevant equations



    3. The attempt at a solution
    I have gotten answers for parts a and b, but I get really confused on part c.

    For a: 1 mph = .447 m/s, so 60(.447)=26.82 m/s. (26.82 m/s)/(10s)=2.68 m/s^2

    For b: g=gravity=9.8 m/s^2. (2.68 m/s^2)/(9.8 m/s^2)=.273(100)=27.3%

    For c: I'm not sure where to start to find my answer.

    I appreciate any help!

    I just solved it! I've worked on part C for about 45 minutes to an hour. I just found an equation that worked, imagine that.

    For c: I used d=Vi(t)+0.5(a)(t^2) So, d=(0 m/s)(10 s)+0.5(2.68 m/s^2)(10^2)=134 m. Then to convert 134 m to feet = 134(39.37)=5,275.58 in/12=440 ft

    Hopefully this will help someone else out that is new to physics, like myself.
     
    Last edited: Jan 13, 2008
  2. jcsd
  3. Jan 13, 2008 #2

    olgranpappy

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    Homework Helper

    use one of them there equations from your textbook:
    [tex]
    x = \frac{1}{2}a t^2 + v_0 t + x_0
    [/tex]
     
  4. Jan 13, 2008 #3
    This is the exact equation I used! Please see the bottom of my previous post, I just finished editing my initial post. I appreciate your help, all of the great help I've received from this forum!
     
  5. Jan 13, 2008 #4

    olgranpappy

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    Homework Helper

    ah. well, that's good.
     
  6. Jan 14, 2008 #5
    Yeah and hopefully your teacher can help... oh wait....
     
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