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Homework Help: Physics Homework Help (acceleration & velocity)

  1. Sep 19, 2004 #1
    Hello,

    I was wondering if anyone could help me with the following question:

    How long does it take for a shoe to drop 75 m from rest? What is the final velocity?

    I have that the acceleration is equal to gravity at -9.8 m/s squared and that the distance is 75 m and the intial velocity is zero but I can't get much further than that. Thanks very very much for your time! :smile:
     
  2. jcsd
  3. Sep 19, 2004 #2

    Pyrrhus

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    Look up kinematic equations
     
  4. Sep 19, 2004 #3

    Simfish

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    y = 75 - 4.9t^2.
    Solve for y = 0.
     
  5. Sep 19, 2004 #4

    Tide

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    We're all waiting for the other shoe to drop! (Sorry - couldn't resist!)

    BTW - I think air drag will be an important factor in this one but I'm sure your textbook isn't interested in that complication.
     
    Last edited: Sep 19, 2004
  6. Sep 19, 2004 #5
    Yea, in most High School Physics text, air resistance is neglected.
     
  7. Sep 19, 2004 #6
    (Vf)^2=(Vo)^2+2ad

    Vf=Final Velocity
    Vo=Initial Velocity
    a=Acceleration
    d=Distance

    *This equation does not include air drag
     
  8. Sep 19, 2004 #7
    ya just use the equation mentioned above and you should be able to get the right awnser. :approve:
     
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