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Homework Help: Velocity equation for quadratic drag, vertically thrown

  1. Dec 16, 2012 #1
    1. The problem statement, all variables and given/known data

    I am having some trouble deriving this velocity equation. I the net force will be

    [itеx] m * dv/dt = - mg - kv^2 [/itеx]

    Because the object is moving upwards. At the time t=0 the velocity will be [itеx]v(0)=v_0[/itеx]
    2. Relevant equations

    3. The attempt at a solution
    Last edited by a moderator: Dec 16, 2012
  2. jcsd
  3. Dec 16, 2012 #2


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    Have you studied differential equations? That is a first order-separable one.

  4. Dec 16, 2012 #3
    Try multiplying the numerator and denominator of the left hand side by v, and using dx = vdt.
  5. Dec 18, 2012 #4
    I am familiar with diff equations of first order. However i can't see what kind it is?
  6. Dec 18, 2012 #5


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    It is a first order, separable one.

    Last edited: Dec 19, 2012
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