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Fluid resistance problem

  1. Nov 19, 2011 #1
    1. The problem statement, all variables and given/known data
    A small rock moves in water, and the force (fluid resistance) exerted on it by the water is given by the equation Fd = kv, where k is a constant. The terminal speed of the rock is measured and found to be 2.0m/s. The rock is projected upward at an initial speed of 6.0m/s. You can ignore the buoyancy force on the rock. Find the maximum height that the rock reaches.

    I'm not quite sure if there is enough information given to actually solve this question. I can't seem to figure out how to start the question either :(
  2. jcsd
  3. Nov 19, 2011 #2


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    Staff: Mentor

    There's enough information. You have to construct and solve a differential equation for the motion of the rock as it rises. Start by finding an expression for the constant k in terms of the terminal velocity and any other relevant constants.
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