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General => General Discussion => Topic started by: rumborak on January 03, 2013, 02:54:52 AM

Title: Calling on all physics geeks
Post by: rumborak on January 03, 2013, 02:54:52 AM
I am trying to remember a certain technique in physics, but just can't think of the name. It's used when calculating forces etc in an equilibrium. What you do is to add an infinitesimal displacement to a border and see what the new energy distribution is. The difference in the energy from the equilibrium energy gives you the force acting on that border.
There is a term for that computational tool, but what is it?
Title: Re: Calling on all physics geeks
Post by: wasteland on January 03, 2013, 03:01:46 AM
Perturbation Theory? Hamilton's Integral Principle?
Title: Re: Calling on all physics geeks
Post by: rumborak on January 03, 2013, 03:03:47 AM
Aaah, found it finally. It's called "Virtual work" and works with the calculus of variations..

This thread can now be about bunnies in a basket.

EDIT: Ooh, pertubation theory is cool too. Thanks!
Title: Re: Calling on all physics geeks
Post by: wasteland on January 03, 2013, 03:05:23 AM
Aaah, found it finally. It's called "Virtual work" and works with the calculus of variations..

This thread can now be about bunnies in a basket.

Hamilton's Principle, then. What's that you have to calculate, for curioisty? :)
Title: Re: Calling on all physics geeks
Post by: rumborak on January 03, 2013, 03:10:15 AM
Interestingly, this has nothing to do with physics at all. I'm writing a paper where I'm optimizing a computational cloud in its configuration, and the method I use is very similar to Hamilton's Principle. Given that I'm already making heavy physical analogies in the paper, I figured I'd mention this too.
Title: Re: Calling on all physics geeks
Post by: wasteland on January 03, 2013, 03:12:02 AM
Interestingly, this has nothing to do with physics at all. I'm writing a paper where I'm optimizing a computational cloud in its configuration, and the method I use is very similar to Hamilton's Principle. Given that I'm already making heavy physical analogies in the paper, I figured I'd mention this too.

It's very interesting. I would probably enjoy the read. Now onto my paper on amplifiers, again...  :-\
Title: Re: Calling on all physics geeks
Post by: Sketchy on January 03, 2013, 04:12:36 AM
Sounds pretty wizard, I must say.
Title: Re: Calling on all physics geeks
Post by: IDontNotDoThings on August 19, 2017, 11:19:54 PM
(necro because it's better than making a new thread)

So does anyone know if there's a formula I can use to determine an initial velocity from an initial force & mass? Like, if you wanted to use the displacement formula: s = ut + at^2/2, would there be a way to get u if all you had was the force you placed on the object & the object's mass? I've looked through my notes & I can't seem to find if there's a formula that relates the three variables directly. I know there's F = ma, but is there a variation on that where you have velocity instead of acceleration? This isn't anything urgent, but I'm working on a simulation & I'm wondering if that formula existed. Thanks in advance.

Edit: Nevermind, I figured it out
Title: Re: Calling on all physics geeks
Post by: JayOctavarium on August 20, 2017, 11:18:15 AM
nerds
Title: Re: Calling on all physics geeks
Post by: Adami on August 20, 2017, 11:18:54 AM
(https://media.giphy.com/media/A9KfKenpqNDfa/giphy.gif)
Title: Re: Calling on all physics geeks
Post by: jasc15 on August 25, 2017, 02:55:01 PM
Hey, I actually knew the answer to this one.  I learned it in a strength of materials class, but haven't used it since.