Dampening effect on a pendulum

[BEEFCOPTER]

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!

 

[kandyfloss]

I guess you use the time period formula for pendulum
T=2pie.sqrt(L/g)

 

[twang]

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

 

[BEEFCOPTER]

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?

 

[PJC01]

I can understand your confusion about the dampening effect on a pendulum. The equation you are looking for is called the damped oscillation equation, which takes into account the dampening effect on the pendulum's motion. This equation is more complex than the simple pendulum period equation, as it also includes factors such as the mass of the pendulum, the strength of the dampening force, and the initial conditions of the pendulum's motion.

To calculate the time it takes for the pendulum to come to a complete stop, you will need to use the damped oscillation equation and solve for the time variable. This will give you a more accurate estimate of the pendulum's motion, taking into account the dampening effect. Keep in mind that the dampening effect will cause the pendulum to lose energy over time, resulting in a decrease in amplitude and eventually coming to a complete stop.

I would suggest consulting a physics textbook or online resources to find the specific damped oscillation equation that applies to your situation, as it may vary depending on the exact setup of your pendulum. I hope this helps and good luck with your project!