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Acceleration of a runner to finish in his desired time

  1. Jun 1, 2012 #1
    1. The problem statement, all variables and given/known data

    A runner hopes to complete the 10,000 meter run in less than 30 minutes, after exactly 25 minutes there are 1900 meters to go. The runner must then accelerate at 0.22 m/s^2 for how many seconds in order to achieve the desired time?

    2. Relevant equations

    V=change in distance/change intime
    avg acceleration=change in velocity/time elapsed


    3. The attempt at a solution

    V before 25 minutes=5.4 m/s
    V after 25 minutes=6.33 m/s
    Avg. Acceleration=.24 seconds (know thats not right)
     
  2. jcsd
  3. Jun 1, 2012 #2
    V before 25 minutes=5.4 m/s=Correct
    Question is what is time taken
    Acceleration given.

    Now we call it u not V
    You have intial velocity 5.4 m/s, distance to cover and use SUVAT to find time needed.
     
  4. Jun 1, 2012 #3

    NascentOxygen

    User Avatar

    Staff: Mentor

    The runner accelerates steadily at 0.22m/s over a time t seconds. Then he runs at that new speed for 300-t seconds.
     
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