By now you've probably seen the viral video below of a concrete block smashing Physics demo gone wrong* (WARNING: disturbing content.) As a veteran Physics teacher who does this demonstration in classes several times a year, both as the "smasher" and as the "smashee," I am assuming that you are about to walk down to my office, email me, or draft a law telling me that I can never perform such a dangerous demonstration in my classroom ever again. Please don't. You shouldn't. Here's why.
1. From a Physics education standpoint, the demonstration is very valuable.