Not going to be alone, not going on hiatus...

[Megas Methuselah]

Ok, here we go:

An 8-meter ladder is resting against a perfectly vertical wall. Suddenly, the bottom of the ladder slides away from that wall at a rate of 0.6 meters per second. How fast is the angle between the ladder and the ground changing when the top of the ladder is 1 meter from the ground?

This is a classic, btw.