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Homework Help: Free falling - Am I doing right?

  1. Jan 5, 2005 #1
    Hi. I'm gonna calculate the time of impact for a free falling object, witch falls from 300 meters without any initial velocity.

    So far I'm thinking I can do something like this.
    y=-4.9t^2 + 300
    -4.9t^2 + 300 = 0
    4.9t^2 = 300
    t^2 ~= 61
    t ~= 7.8

    Answer: The impact takes place 7.8 seconds after the drop of the object.

    I'm assume I'm doing something wrong, so I'm really glad if anybody takes some time and look at this.
  2. jcsd
  3. Jan 5, 2005 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Looks good to me (neglecting air resistance, of course).
  4. Jan 5, 2005 #3
    You got it right!
  5. Jan 5, 2005 #4
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