How I do I make controls/elements move with inertia?

Question

Modern UI\'s are starting to give their UI elments nice inertia when moving. Tabs slide in, page transitions, even some listboxes and scroll elments have nice inertia to them (

Answer 1

Mike F's got it: you apply a time-position function to calculate the position of an object with respect to time (don't muck around with velocity; it's only useful when you're trying to figure out what algorithm you want to use.)

Robert Penner's easing equations and demo are superb; like the jQuery demo, they demonstrate visually what the easing looks like, but they also give you a position time graph to give you an idea of the equation behind it.