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Homework Help: Kinematics Equation help

  1. Jun 5, 2012 #1
    A runner hopes to complete the 10,000m run in less than 30.0 minutes. After exactly 27.0 minutes, there are still 1100m to go. The runner must then accelerate at 0.20m/s^2 for how many seconds in order to achieve the desired time.

    I have calculated the runner moving at 5.5m/s^2 for the first 27 minutes. I have no idea how to calculate this problem, all I know is that it will need to be divided into two parts.

    With 180 seconds remaining, the runner would need to be going 6.1m/s^2 to complete the race on time. So they will need to accelerate about .6m/s^2 which is about 3 seconds, but I don't know what equations I need to plug into one another to show my work for this problem.
  2. jcsd
  3. Jun 5, 2012 #2
    It's 5.5 m/s
    You have initial velocity, acceleration and and distance. Use SUVAT formula to solve the time taken.
  4. Jun 8, 2012 #3
    I think you must use d=vit+0.5at^2 or a variation of that.
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