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Homework Help: Circular and projectile motion

  1. Apr 24, 2008 #1
    [SOLVED] circular and projectile motion

    1. The problem statement, all variables and given/known data
    In the Olympic hammer throw, contestants whirl a 7.3 kg ball on the end of a 1.2 m long wire before releasing it. Suppose the hammer is released frim a height of 1.3 m while moving in a direction 24 degrees above the horizontal. If it travels 84 m horizontally, what is its radial acceleration just before release.
    The book answer is a = 892 m/s^2

    2. Relevant equations
    y = x tan theta - gx^2/2v0^2 cos^2 theta

    a = v^2/r

    3. The attempt at a solution

    1.3 = 84 (.445) - 9.8 (84)^2/2v0^2 (.914)^2

    v0^2 = 41386.8/36.1 = 1146.4

    a = 1146.4/1.2 = 955 m/s^2

    Even if I just use the velocity in the x direction, it does not work.
  2. jcsd
  3. Apr 24, 2008 #2
    The starting height is 1.3 m. The height when x=84 is 0 m
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