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Homework Help: Kinematics Equations (Basic)

  1. Oct 5, 2009 #1
    1. The problem statement, all variables and given/known data

    Pelicans tuck their winds and free fall straight down when diving for fish. Suppose a pelican starts its dive form a height of 20.0 m and cannot change its path once commited (uniform motion). If it takes a fish 0.1 s to perform evasive action, at what min height must it spot the pelican in order to escape

    2. Relevant equations

    No Clue

    3. The attempt at a solution


    I have tried in numerous times but was away for a lesson and dont have a clue to what is going on

    Please Help
    Last edited: Oct 5, 2009
  2. jcsd
  3. Oct 5, 2009 #2


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    Homework Helper

    Find the time t taken by the pelican to reach the water from 20 m.
    Then find the distance covered by the pelican in (t - 0.1) seconds. And proceed.
  4. Oct 5, 2009 #3
    You will need [tex]s=y_{i}+v_{i}t+\frac{1}{2}at^{2}[/tex]

    How long does it take the pelican to free fall to the water? How much time before that must the fish react?
  5. Oct 5, 2009 #4
    OO thanks for the reply guys. Do you know where i can get a list of all these equations (kinematics)
  6. Oct 5, 2009 #5
    Do you have a textbook?
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