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Homework Help: Horizontal Kinematics

  1. Feb 21, 2008 #1
    1. The problem statement, all variables and given/known data
    A world-class sprinter can burst out of the blocks to essentially top speed (of about 11.5m/s) in the first 15.0m of the race.
    a.) What is the average acceleration of this sprinter?
    b.) How long does it take her to reach that speed?

    2. Relevant equations

    3. The attempt at a solution
    I hope that I have solved the problem correctly. I drew a picture and followed a 12 step process assigned by my teacher. I just want to know if my answers are correct to know if what I am doing on the rest of my homework is correct.
    a.) a= 4.408 m/s^2
    b.) t= 2.608 s
  2. jcsd
  3. Feb 21, 2008 #2
    a. Well, vf^2=vo^2+2ad, vo=0
    a ends up to be 4.40833333m/s^2
    b.vf=v0+at, vo=0
    t ends up to be 2.60869565s
    so both answers are correct
  4. Feb 21, 2008 #3
    2.609...(according to silvershadow)

    Sorry to be pedantic ;p
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