Acceleration of mass

Question

Two flexible balls rolling along a frictionless horizontal surface collide with each other. The larger of the balls weighs 50 g and the smaller weighs 30 g. Immediately after the balls first touch each other (the beginning of the collision), the center of mas of the larger ball is accelerating at a rate of 5 m s^-2 to the right.

What is the acceleration of the center of mass of the smaller ball?

Answer 1

Newton's third law says that there is equal but opposite force acting on the smaller ball, thus

30 * a = 50 * 5m/s²

So a = 8.33 m/s² for the smaller ball, but the direction's to the left.