7. A billiard ball is shot east at 2.10 m/s. A second, identical billiard ball is shot west at 1.10 m/s. The balls has a glancing collision, not a head-on-collision, deflecting the second ball by 90 and sending it north at 1.50 m/s. What is the speed of the first ball after the collision? m/s initially at cost of mass 0.54 ka Aca