A steel ball of mass moving with a velocity of 2.0 m/s [E], strikes a 1.2 kg copper ball initially moving 1.0m/s [W]. The collision is a glancing one, causing the steel ball to have a velocity of 1.5 m/s [W 30 degrees N] and the copper to move in the direction [E 47 degrees S]. Is the collision elastic? There seems to be so many unknowns in this question, which is why I seemingly can't combine any formulas. How should I attempt to solve this?