I'm confused about "Each component must also be conserved". Why are all three components still conserved when the two balls collide in such a way that alters their motion perpendicular to the shadow plane?
Alright, two balls are moving in the exact same direction with one slightly higher than the other parallel to the shadow plane. One is moving faster than the other and they collide in an elastic collision. Both balls lose translation speed in the shadow plane. Momentum is conserved in 3D, and...
But how can either A or B be correct is speed is lost due to distortion? (If you're implying that)
There can be a case of ratio of the speeds not changing since we can make this counter example to be perfectly symmetrical. (Which I think would rule out KE being the same, while momentum isn't)...
Homework Statement
Suppose that two elastic balls moving through three dimensional space collide and rebound, conserving both kinetic energy and momentum. The balls cast shadows, and these shadows moving over a flat two-dimensional surface come together, collide and rebound. Now pretend the...