In one of my lesson plans, I challenge students to build a level in which they have to use perfect timing to catch a cube that’s launched with a momentum fling. The simpler the setup, the better. Here’s an example of such a level.
Of course, the math behind a momentum fling is pretty easy. Making the catch is all about putting the moving platform in the right place at the right time.
I’ll be reusing this level for an upcoming video on the effects of friction in Portal 2.
Physics with Portals 