Hi Prof Fu-Kwun Hwang,

I'd like to share this simulation which I've been working on with Loo Kang. But I need your help to modify the formula/code such that when the wrecking ball hits the building, it stops.

I've designed a lesson around this simulation whereby students play a demolision contractor and are supposed to describe how energy is converted from one form to another when the ball hits the building.

Thank you!