amp = 50;
freq = 2;
decay = 5;
n = 0;
if (numKeys > 0 && time > key(numKeys).time) {
t = time - key(numKeys).time;
n = Math.sin(freq * t * Math.PI * 2) * amp * Math.exp(-decay * t);
}
value + [n, n];
A ball bounces to a stop after falling, using this expression to animate its bounce motion.