1. The problem statement, all variables and given/known data Q: A 3.000u object moving to the right through a laboratory at 0.8c collides with a 4.000u object to the left of the laboratory at 0.6c. Afterward, there are two objects, one of which is a 6.000u mass at rest. A) what are the mass and speed of the other object? B) determine the change in kinetic energy in the collision 2. Relevant equations γ1m1v1 + γ2m2v2 = γ3m3v3+γ4m4v4 γ1m1c2+γ2m2c2 = γ3m3c2+m4c2 3.= The attempt at a solution I've been struggling with this for a while, and haven't really made much headway. The part I'm finding difficulty with is using both conservation of momentum and conservation of energy formulas when I need to consider that the third particle technically isn't moving. I don't necessarily want the answers handed to me - just a few tips to get me headed in that direction would be much appreciated.