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Initial velocity

  1. Sep 6, 2003 #1
    Can someone please help me

    A diver spings upward from a board that is three meters above the water. At the instant she contacts the water he speed is 8.90m/s and her body makes an angle of 75 degrees with respect to the horizontal surface of the water. Determine her initial velocity, both magnitude and direction.:wink:
  2. jcsd
  3. Sep 6, 2003 #2


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    We don't tend to do homework for people. If you take a crack at this and tell us where you're getting hung up then we can help from there.
  4. Sep 6, 2003 #3
    I just need to know the formula or the way to go about it
  5. Sep 6, 2003 #4
    I'm surprised you don't have any formulas in your textbooks.
    Since I don't want to give away everything, I'd say you should draw the situation for yourself in which you write the speed, the distance, etc.
    I think this would help you solve your problem.

    Hint: think of where the speed of the diver comes from, think of gravity :wink:
  6. Sep 6, 2003 #5


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    For this question, you must show lots of Resolve...
  7. Sep 7, 2003 #6
    As I did watch the swiming world championship not more than a month ago I'd like to say that comparing a diver to a stick like the author of this problem is a sign he shouldn't do this for a living. Physics is about life so good connections to life are required when you try to compose problems. All good divers enter the water at about the same angle (as close to the vertical as possible) because they are judged by the splash they make and about at the same speed (it is actually free fall), but they start in a lot of different positions and rotate a lot in the air.

    Regarding the solution, think that the stick is always tangent to its trajectory (it wouldn't make much sense for it to rotate in the air, I mean you couldn't solve the problem), get those parabola parameters and find its derivative in the initial point.
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