Resonance

Alright so let's talk about Resonance, so what is Resonance? Resonance is forced motion that somehow in tune with the natural oscillation frequency of a system and that's called the resonant frequency. Alright so there's lots of different ways that we can understand this. If I've got a pendulum right here and I just let it go it's got a certain frequency associated with it.

Now if I start hitting it if I hit it at the wrong frequency, it doesn't do anything really I mean it just kind of does whatever my hand ask it to do. But if I hit it at the resonant frequency, so now I'm going to hit it every time its over there it increases its amplitude so that's the idea whenever you have resonance, it means that you're pushing the system the right direction every time so that means that that system it's going to increase its amplitude basically until it breaks.

Now you've also heard of this when you've got something like a glass every object has its own resonant frequency and you can hear that resonant frequency by hitting it when you tap it, it sings its resonant frequency so the frequency of that sound wave is the frequency of natural oscillation of this glass and of course you've heard of that when you've heard of opera singers you're able to sing at a wine glass and break it what they're doing is they're exciting that glass and it's own natural resonant frequency and that increases its vibrations in amplitude until the glass just can't take it anymore and it breaks.

Alright, another major example of resonants was galloping gully which is at the bridge in state now in 1940 during a storm the wind blew this bridge wow blew this bridge at the resonant frequency and the thing started oscillating and oscillating and oscillating and eventually just broke I think it took like 2 hours I heard that nobody was killed or anything everybody got off but that was resonance at galloping gully and that's Resonance.