Pleat Swing Physics?

[The Guy in the Kilt at UC]

Physics Analysis....

For T=(2*pi)*sqrt(Length/g) where g=gravity=-9.8m/s^2

Using the length of my kilt that isn't sewn down as the pendulum, I'll assume length to be 15"

If I wanted to optimize the swing of my kilt, i would take one step every 1.3 seconds.

Voila. You can use that formula to figure out what pace you need to walk to get the maximum swing in your kilt.

(By the way, I'm an Engineering student... so this stuff is still fresh. I bet the Wizard could have gotten this one had he read it first.)

I'm sorry to say that it is not that simple (though it may be very close). The problem is that each pleat is coupled to another on each side. What you will need to do is find (one of) the natural frequencies to find maximum swing. This will depend on the number of pleats. Also it will depend on the size of your seat. Because your curvature will ensure that they are not swinging in the same direction. That is, they will want to swing left & right in back as you look at it straight on, but they will want to swing back & forth on the sides as you look at it straight on (albeit a much smaller swing). I imagine that things such as the weight of the wool will not matter much if you can make a generality.

I think I just found something to procrastinate with today.

[george7]

I'm sorry to say that it is not that simple (though it may be very close). The problem is that each pleat is coupled to another on each side. What you will need to do is find (one of) the natural frequencies to find maximum swing. This will depend on the number of pleats. Also it will depend on the size of your seat. Because your curvature will ensure that they are not swinging in the same direction. That is, they will want to swing left & right in back as you look at it straight on, but they will want to swing back & forth on the sides as you look at it straight on (albeit a much smaller swing). I imagine that things such as the weight of the wool will not matter much if you can make a generality.

I think I just found something to procrastinate with today.

Connecting the pleats and assuming that they swing in different directions doesn't change the resonance, just the dampening. The period of a pendulum tied to another pendulum of equal length will result in a system of pendulums with the same frequency. If you weave them together, they'll dampen each other, but it won't change the frequency they prefer.