One billiard ball is shot east at 3.5 m/s. A second, identical billiard ball is shot west at 2.1 m/s. The balls have a glancing collision, not a head on collision, deflecting the second ball by 90 degrees and sending it north at 1.8 m/s.
a. Find the final speed of the first ball.
b. Find the direction of the first ball after the collision (angle below the West-East line.)