A 0.200-kilogram ball A is traveling at a velocity of 2 meters/second. It hits a 1-kilogram stationary ball B. Which statement is true of the motion of the balls if the collision is elastic?

{M (a) * V (a) + M (b) * V (b) } initially = {M (a) * V (a) + M (b) * V (b) } finally

0.2 * 2 + 0 = 0.2 V (a) + V (b)

0.4 = 0.2 V (a) + V (b)

2 = V (a) + 5V (b)

Now apply conservation of energy

1/2 * 0.2 * 4 + 0 = 1/2 * 0.2 * [V (a) ]² + 1/2 * 1 * [V (b) ]²

Solve the two equations and you would get Vb = 2/3

and Va = - 4/3 ( - indicates opposite direction)

Hence

D. The balls separate and move in opposite direction

I think it is D im not for sure