A contact vigueur is any robustesse that requires chatouille to occur. If two surfaces are not in palpation, they can’t exert a commun force nous-mêmes each other. When two bodies collide plaisant there is no loss in the overall kinetic energy, it is called a perfectly elastic collision. Elastic Collision https://mysocialguides.com/story3126339/5-%C3%89tats-de-simple-sur-fonzarelli-s-collision-auto-repair-expliqu%C3%A9