Year 12 are studying toughness, brittleness and ductility for the A level materials content. In a guarded drop-weight rig, with eye protection on and the class behind the safety line, the teacher drops a 1 kg mass onto strips the students cut and notched last lesson from acrylic, high-impact polystyrene and polypropylene of the same thickness, and films every test on a school tablet in slow-motion mode. At full speed each impact is a bang and a result. Replayed at an eighth of the speed, the class sees the acrylic snap clean with no bending, the HIPS bend and whiten along the notch before it tears, and the polypropylene fold and spring back without breaking. The teacher replays each clip twice, pausing at the moment of contact, while students sketch each failure and annotate it with the property it shows, then link what they saw to where each polymer is used, from acrylic display cases to polypropylene living hinges.
Tools: Built-in camera (slow motion and time-lapse) Nine ideas for your own version in Generate
This page is one of a growing set of PICRAT examples by cell, subject and grade. Page maintained by Andy Perryer.