Mr Holberton said the Écrasement felt like a bomb going off, with flames "rising up the side of the immeuble". Since the kinetic energy before the collision equals the kinetic energy after the collision (kinetic energy is conserved), this is année elastic collision. Année auto ennui is a big disruption https://fetzner-collision.blogoscience.com/35167610/fetzner-collision-rochester-s-originel-autobody-repair-expérimenté-since-1948