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

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Discussion Overview

The discussion revolves around the formulas for calculating the velocity and time taken by an object falling in water, considering factors such as mass, density, volume, height, and drag force. Participants explore different approaches to modeling this scenario, including the implications of drag force on the motion of the object.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant inquires about the specific formula for velocity and time taken for an object falling in water, noting the importance of drag force in the calculations.
  • Another participant suggests that Stokes' law of resistance is a simple approximation for drag force, but acknowledges that the problem lacks a straightforward solution in general.
  • A different participant references a recent achievement by a young individual who reportedly solved the mathematics of objects falling with air resistance, implying potential relevance to the water scenario but noting the need for adjustments.
  • Another participant recalls a historical anecdote about Stokes deriving his formula during a physics exam, highlighting the complexity and intrigue surrounding the topic.

Areas of Agreement / Disagreement

Participants express varying perspectives on the applicability of Stokes' law and the complexity of the problem, indicating that multiple competing views remain without a consensus on a definitive formula.

Contextual Notes

The discussion does not resolve the specific assumptions or conditions under which different models apply, nor does it clarify the mathematical steps necessary for calculations involving drag force.

malek340
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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?
 
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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:
http://en.wikipedia.org/wiki/Drag_(physics)
 
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 that's been done yet
 
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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