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Homework Help: Distance of airplane.

  1. Sep 25, 2011 #1
    1. The problem statement, all variables and given/known data
    Assuming equal rates of acceleration in both cases how much further would you travel if braking from 56mi/h to rest than from 28mi/h ?
    a, 5.2 times farther
    b, 4.8 times farther
    c, 3.2 times farther
    d, 4.0 times farther

    2. Relevant equations

    not really sure what i should use.
    v=v0+at
    x= x0+2a(x-x0)
    3. The attempt at a solution
    0-56/0-28=56/28=2
     
  2. jcsd
  3. Sep 25, 2011 #2
    V1 (56 m/s) is twice as great as V2 (28 m/s) so the time needed to stop is going to be doubled, due to a the equal acceleration. So you take the difference in the velocity values (twice as great), and in the time values (twice as great), and you come up with the four times farther by multiplying the aforementioned values.
     
  4. Sep 25, 2011 #3
    ohh. thank you!
     
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