1. The problem statement, all variables and given/known data A 0.045kg Steel marble collides obliquely with an identical stationary marble, and continues at 55 degrees to its original direction. The collision is perfectly elastic. What is the angle between the direction taken of the target (previously static) ball and the original direction of the incident ball? So: m1: 0.045 kg v1: >0m/s p1: >0m/s m2: 0.045 kg v2: 0 m/s p2: 0 m/s p= m1v1 p'=m1v1 + m2v2 p = p' θ1': 55 degrees above or below previous. θ2': ? 2. Relevant equations p = mv p = m1v1 + m2v2 p' = m1v1' + m2v2' p = p' Sine Law Cosine Law 3. The attempt at a solution Manipulating several formulas to find a result that required so few variables. No real luck there. Attempted to build a system where I added some variables, like v1' but that was unfruitful, given that the incident was feigned anyway. Any suggestions are certainly appreciated.