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Homework Help: Need help on Motion in a Resistive Medium

  1. Sep 22, 2008 #1
    1. The motion of a body falling from rest in a resistive medium is dv/dt = Bv - Av^2.

    2. Find it's initial acceleration.
    Find the velocity at which the acceleration becomes zero.

    3. B and A are constants.

    dv/dt = acceleration = Bv - Av^2.

    vf = vi + at
    vf = 0 + Bv - Av^2(t)
    vf = Bv - Av^2(t)

    Where am I going with this?
  2. jcsd
  3. Sep 22, 2008 #2
    dv/dt is acceleration.

    a. So, when it says find the initial acceleration you just set v=0.
    a= B(0) - A(0)2

    b. To find the velocity at which accleration becomes 0, you set the whole equation to 0.
    0=Bv - Av2
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