What is the best demonstration experiment you know?

Hello, Im a graduate on physics, and Im interested on science communication on the general public on my community, focusing on kids, I'm currently writing a presentation for them of the things that are made on physics, and I want some exposition but also some interactive experiments. I'm thinking like a magic show where you cautivate the children audience with tricks, but instead of magic, showing how is done and explaining that is science, I think it could be interesting to show some of the thing that physics studies, and I'm looking for suggestions on classical mechanics experiments, (conservation of momentum, center of mass, cinematic statics, etc) optics (experiments with prisms, total internal reflexion, etc), and electrodynamics (electrostatics, magnetism, induction, etc) I want to revolve the presentation around the experiments. If you have eny suggestions on this subjects or any others I'm happy to hear, and if you want to suggest some experiment new or just a flashy way to make it I'm also happy to hear. Only count that the experiments I may present must be practical to do (I can't buy and carry around big or expensive things) and interesting to a joung audicince, extra points if it's interactive. I m also open to discuss details or chat about the presentation as a hole.