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Homework Help: Finding uniformly increasing acceleration.

  1. Dec 3, 2011 #1
    1. The problem statement, all variables and given/known data

    What is the acceleration of a rocket that travels uniformly from rest and travels 650m in the first 12 seconds.


    2. Relevant equations

    [tex]s=v_it+\frac{1}{2}at^2[/tex]

    [tex]a=\frac{\Delta v}{\Delta t}[/tex]

    3. The attempt at a solution

    I pluged the acceleration equation in to the first equation.

    [tex]s=0(12)+\frac{1}{2}\frac{650}{12}12^2[/tex]

    that equaled 7800 m/s squared. That is so far off. The answer is 9 m/s squared.
     
  2. jcsd
  3. Dec 3, 2011 #2

    cepheid

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    Staff Emeritus
    Science Advisor
    Gold Member

    You dont need the second equation, and it's not useful because you don't know what the change in v was.

    The first equation is perfectly adequate. You know s, you know vi and you know t. Solve for a.
     
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