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Homework Help: Analyzing the kinematic x(t) equation

  1. May 25, 2009 #1
    1. The problem statement, all variables and given/known data

    Solve the equation below for deltaX symbolically and simplify the answer as much as possible.

    deltaY = (tan A)deltaX - g*deltaX^2/2V(initialx)^2

    2. Relevant equations
    quadratic equation.

    3. The attempt at a solution

    I can handle the algebra and simplification. My question comes as I analyze the equation as a kinematics problem. I assume the fnal term was gotten by the equation:

    V(final)^2 = V(initial)^2 + 2ax. Therefore V(final) = 0 so there is a deceleration. But g is divided by this accel so I guess g is dependent on this acceleration??

    I also found, that given the velocity v time graph, V(initial) = tan A.

    Why wasn't this value used in the g*deltaX^2/2 V(initialx)^2 term?

    Finally, because I don't see any t in the equation, I assume it can be used in terms of deltaX as well?? Or was the professor just testing our understanding of the quadratic equ?

    Does this quation describe any familiar motion?
    Last edited: May 25, 2009
  2. jcsd
  3. May 25, 2009 #2


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    Homework Helper

    deltaY = (tan A)deltaX - g*deltaX^2/2V(initialx)^2
    Dimensionally this equation is not correct. One t is missing.
    I also found, that given the velocity v time graph, V(initial) = tan A.
    V initial cannot be tanA
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