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Average Velocity and Constant Acceleration

  1. Mar 11, 2010 #1
    Can some one please prove that Vav=(Vi+Vf)/2 is valid only for constant acceleration?
  2. jcsd
  3. Mar 11, 2010 #2


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    Science Advisor

    No, because it isn't valid only for constant acceleration. There are other velocity functions that also yield this average velocity.
  4. Mar 11, 2010 #3


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    It's posible for Vav=(Vi+Vf)/2 to be true for variable acceleration as well. Start off with a graph of velocity (y axis) versus time (x axis). Then the area below the horizontal line that goes from {t0, Vav} to {t1, Vav} = Vav x (t1 - t0) = the distance traveled. Then note that any line of any shape with the same amount of area under the line from {t0, Vi} to {t1, Vf} would also have the same average velocity as constant acceleration.
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