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Homework Help: Projectile Motion

  1. Sep 18, 2004 #1
    suppose that you found a victim on the pavement below a 4th story window (window sill 10m above the pavement). He is lynig 7m from the base of the wall. You are suspicious about this situation. The victim appears to have died from a fall. If the body has a mass of 65kg and the average human leg can produce a force of 2500 N over a distance of 0.1 m. Is it possible for the victim to land where they did given the above criteria? (note you are not permitted to use an energy argument to solve this question. Use the data to solve this using dynamics and kinematics equations)

    The thing that really bugs me about this question is the 2500 N over a distance of 0.1 m. I assume from that you would find the initial velocity. However, I have no idea how to do so.
  2. jcsd
  3. Sep 18, 2004 #2
    Is it ok if i said that F = ma. Therefore a = 2500/65.

    And than plug that into Vf^2 = Vo^2 + 2ax and solve for vf.

    Than use that as the initial velocity for the projectile motion period. And assume that Vf is in the x-direction. That way i can see if it is possible for the person to have landed 7 m away.
  4. Sep 18, 2004 #3


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    Homework Helper

    Well, i believe so, try that.

    I mean if you analyze that's 10 cm, so the legs produces that average force in that distance, wich could be the distance in the window frame, considering the distance used for Walls depht is usually 0.2 meters.
    Last edited: Sep 18, 2004
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