Dampening effect on a pendulum

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    Pendulum
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Discussion Overview

The discussion revolves around the effects of damping on a pendulum's motion, specifically how to calculate the time it takes for a pendulum to come to a complete stop due to damping forces. Participants explore the relationship between the pendulum's physical properties and the damping effects caused by friction and air resistance.

Discussion Character

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

Main Points Raised

  • One participant seeks an equation to determine the time until a pendulum stops, acknowledging they have the necessary variables but are unsure how to account for damping effects.
  • Another participant suggests using the time period formula for a pendulum, T=2π√(L/g), but does not address the damping aspect directly.
  • A third participant argues that the time a pendulum continues to swing is dependent on the specific sources of friction, including pivot point friction and air resistance, indicating that these factors must be known to calculate the damping force accurately.
  • A later reply questions how to represent the total time until the pendulum comes to rest if the total coefficient of friction is known, indicating a need for a specific equation that incorporates these damping factors.

Areas of Agreement / Disagreement

Participants do not reach a consensus on a specific method or equation for calculating the time until the pendulum stops. Multiple views on the influence of damping forces and the need for specific friction values remain contested.

Contextual Notes

The discussion highlights the complexity of damping effects on pendulum motion, with limitations noted regarding the need for empirical data on friction sources and the lack of a clear equation for total stopping time.

Who May Find This Useful

Individuals interested in the dynamics of pendulum motion, particularly in the context of experimental setups or engineering applications involving damping effects.

BEEFCOPTER
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Ok, my mind has gone blank. What equation do I use to calculate the time a pendulum will take to come to a complete stop?.. I have all variables, length of string, angle it was released, etc.. I know the equation for period, but how do I figure how long till it stops from DAMPENING effect..?

This isn't really a homework question, its just for something I am building. So hopefully this is the right place to post. Thanks!
 
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I guess you use the time period formula for pendulum
T=2pie.sqrt(L/g)
 
That would vary from pendulum to pendulum... there's no way to calculate how long it keep swinging without knowing the sources of friction. There's friction 1. in the bearing of the pendulum's pivot point (unless its a wire tied to a point, in which case there's energy lost in the wire) 2. between the surface of the pendulum's weight or 'bob' and any gas or liquid it's swinging in.

Once you know that damping force (experiment) you can use the equation here: http://en.wikipedia.org/wiki/Pendulum
 
Ok, so, forgive me if these questions are remedial, physics is not my strongest subject. So: If, knowing the total coeffeicient of friction (of the pivot point, as well as the air resistance) what equation would represent total time until the pendulum comes to rest?
 

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