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Homework Help: Projectile motion equation help

  1. Aug 6, 2005 #1
    This question was on my last test, and I got it wrong. If anyone could help me understand how to get the answer, I would really appreciate it!

    A small metal ball with a mass of m = 91.7 g is attached to a string of length
    l = 1.57 m. It is held at an angle of q = 47.5° with respect to the vertical.
    The ball is then released. When the rope is vertical, the ball collides head-
    on and perfectly elastically with an identical ball originally at rest. This
    second ball flies off with a horizontal initial velocity from a height of h =
    3.19 m, and then later it hits the ground. At what distance x will the ball

    I'm not even really too sure on how to approach it!
  2. jcsd
  3. Aug 6, 2005 #2
    you would use projectile motion on this one as well as angular acceleration.

    ar = v^2 / r

    the range of the projectile isd given by
    R = (v062 * sin (2 theta)) / g
  4. Aug 6, 2005 #3
    Thanks a lot for the help, but is there anything else you can tell me. What's throwing me off is that I'm not sure how to find the velocity. I feel like i'm overlooking something simple :confused:
  5. Aug 6, 2005 #4
    first you would use the equation

    a = g sin (theta)

    then intergate to find vel
  6. Aug 6, 2005 #5
    Got it, thanks so much!
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