Two carts, cart AA (mass 4.00 kgkg) and cart BB (mass 6.50 kgkg) move on a frictionless, horizontal track. Initially, cart BB is at rest and cart AA is moving toward it at 4.00 m/sm/s. The carts are equipped with ideal spring bumpers, meaning they conserve energy. The collision is head-on, so all motion before and after the collision is along a straight line. Let x x be the direction of the initial motion of cart AA.

waves moving from a fast medium to a slow medium will experience a reflection as light travels more slowly than red light. total internal reflection occurs when the critical angle is.

blue light is scattered in different directions by the tiny molecules of air. blue is scattered more than other colours because it has a shorter distance to travel which results in smaller waves. this is why we see a blue sky most of the time.