These parents tried inertia challenge with their kids. The mom stacked three cups, with a piece of paper between them. She then pulled the papers away so that the cups fall inside each other. They also tried various other tricks with empty bottles and landed small objects inside them.br br *The underlying music rights are not available for license. For use of the video with the track(s) contained therein, please contact the music publisher(s) or relevant rightsholder(s).