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Homework Help: Help with Projectile Motion

  1. Sep 16, 2004 #1
    Hi, can someone please tell me how to figure out the initial (horizontal) velocity of a ball that rolls horizontally off a cliff at a height of 1.5 m from the ground, and lands 3 m away from the edge of the cliff?
    Last edited: Sep 16, 2004
  2. jcsd
  3. Sep 16, 2004 #2
    u_horizontal *t = 3
    1.5 = 0*t+(1/2)*g*t^2

    -- AI
  4. Sep 16, 2004 #3


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    How long does the ball take to reach the ground? How fast does it have to travel horizontally to be 3 m out in that time?
  5. Sep 16, 2004 #4

    The problem is....the question doesn't give the time or speed. :cry:
  6. Sep 16, 2004 #5


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    You can always combine equations.
  7. Sep 17, 2004 #6
    Yes, that worked. Thanks a bunch! :smile:
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