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Homework Help: Ski Slope

  1. Oct 12, 2007 #1
    A skier (m=59.00 kg) starts sliding down from the top of a ski jump with negligible friction and takes off horizontally. If h = 7.70 m and D = 12.90 m, find H.

    img:http://i242.photobucket.com/albums/ff106/jtdla/prob21a.gif [Broken]

    I was given a hint to treat the skier as a projectile, so I broke the skier's position into two parts.

    yf=yi+vt+1/2gt^2
    0=7.70+Vt+4.7t^2

    xf=x0+Vt
    12.9=0+vt
    then solve for t in the x
    12.90/vt

    so I sub that back in to y

    0=7.70+v(12.90/v)-4.7(12.90/v)^2

    I get a velocity of 8.89 m/s

    am I doing this right
     
    Last edited by a moderator: May 3, 2017
  2. jcsd
  3. Oct 12, 2007 #2
    6.2915 m/s, I just realized that I used 4.7 instead 4.9

    I also got H=13.38m

    Am I about right?
     
    Last edited: Oct 12, 2007
  4. Oct 12, 2007 #3
    any response please?
     
  5. Oct 12, 2007 #4

    learningphysics

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    Homework Helper

    In the vertical direction when the person is going off the ramp horizontally:

    dy = v1y*t + (1/2)at^2, but v1y = 0

    dy = (1/2)at^2

    dy = -4.9t^2

    plug in dy = -7.7

    -7.7 = -4.9t^2

    solve for time. then get the horizontal velocity using D = v*t

    Then use energy...

    mgH = mgh + (1/2)mv^2
     
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