Failure of brittle materials using simple experiments- Part 2

Here is my second video, where I tried to explain the concepts of stress state, principal stresses, Mohr circle and failure theories in layman's language and associated these concepts to explain the failure of a brittle material. This is an educational outreach initiative mainly targeted at the undergraduates (mechanical/civil/aerospace and materials engineering) studying mechanics and also other mechanicians that seek simpler explanations. Kindly share if you learn something out of this !
 Link to my youtube channel : Mechanicians classroom