Two identical molecules, A and B, move with the same horizontal velocities but opposite vertical velocities. Which of the following is always NOT true after they collide:
A - the sum of kinetic energy before collision is less than the sum after
B - the sum of kinetic energy before collision is greater than the sum after
C - molecule A will have greater momentum after the collision than molecule B
D - molecule A will have greater vertical velocity than molecule B
The Attempt at a Solution
Since they don't mention if the collision is elastic or inelastic, either A or B can be true. But I can't distinguish between C and D.
(The right answer is D)