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Homework Help: Need help on this work energy question

  1. May 20, 2007 #1
    1. A car changes velocity from 25m/s to 8.0m/s. If the average force applied to the brakes is 16000N, how far does the 2300kg car go in this time?

    2. How much work is done if a 75kg runner speeds up from 1.2 m/s to 4.0m/s in 1.7s? How much extra work is done if there is a force of friction against the runner of 26N?
  2. jcsd
  3. May 21, 2007 #2
    Hey, moela, welcome aboard!

    You need to show work before we can help.
  4. May 21, 2007 #3
    You can start off by calculating what you can.
    For example if you know the mass and the speed what can you find out?
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