Two particles with masses m and 3m are moving toward each other along the x axis with the same initial speeds vi. Particle m is traveling to the left, while particle 3m is traveling to the right. They undergo an elastic glancing collision such that particle m is moving downward after the collision at right angles from its initial direction.
(a) Find the final speeds of the two particles.
(b) What is the angle θ at which the particle 3m is scattered?