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Homework Help: Using Kinematic equations to describe a falling object

  1. Dec 9, 2007 #1
    1. The problem statement, all variables and given/known data

    For this project, we had to build a vehicle that would hold an egg, and drop it a distance of about 40 feet, and making sure the egg wouldn't break. There are various parts to the report part of this project, and I had a question about the first part. Basically, one part asked:

    Controlling Vehicle Speed: Kinematics
    Use kinematics equations to analyze the vehicle as it falls and explain how you kept the vehicle from striking the ground at an excessive speed.

    2. Relevant equations

    All the kinematic equations, so like:

    vf^2 = v0^2 + 2ax
    vf = v0 + at
    x = v0^2 + 1/2at^2
    x = vf^2 - 1/2at^2

    3. The attempt at a solution

    So this is what I put for the first equation, vf^2 = v0^2 + 2ax:

    One equation to use is vf2 = vo2 + 2ax. For this, x is a value that is constant, basically the distance of about 40 feet, the height at which the vehicle is dropped. v0 is equal to 0, as this was the initial velocity. Therefore, to make vf, the final velocity smaller, the acceleration must be smaller. By putting a "circular disk" around the vehicle, this created air resistance, and lowered the acceleration, thereby lowering the final velocity and impacting the ground at a lower speed.

    What do you think of this, is it good enough? Also, how can I implement the equations:

    vf = v0 + at
    x = v0^2 + 1/2at^2
    x = vf^2 - 1/2at^2

    into this as well, to make it tie in with the vehicle and all? This is graded fairly hard, so I am looking for some good opinions. Would really appreciate the help, thanks :)!
  2. jcsd
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