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What is the formula for velocity and time taken of object falling in water

  1. Jul 17, 2012 #1
    What is the formula of the velocity and time taken of an object faling in water? I have the mass, the density, the volume of the object and the height distance of the falling object. I know that the drag force is included in the formula but i have idea how to calculate it. So anyone knows this?
  2. jcsd
  3. Jul 17, 2012 #2


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    Well, Stoke's law of resistance is the simplest approximation, and in many cases good enough.
    In full generality, the problem does not have any simple answer.
    Look at the subsection concerning Stokes drag:
  4. Jul 19, 2012 #3
    i read about how a kid about 15 years old just cracked (within a month or 2 ago) the math behind objects falling with air resistance. id imagine its related to that although it would need to be tweeked, and its doubtful thats been done yet
  5. Jul 19, 2012 #4


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    I seem to remember a story that Stoke managed to get his formula whilst sitting a Physics exam in which the Professors had put the 'unanswerable' question of a sphere falling through a fluid, just to give students a hard time. (Ah, those were the days!)
    His correct answer caused quite a stir.
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