1. The problem statement, all variables and given/known data Consider an elastic collision (ignoring friction and rotational motion). A queue ball initially moving at 2.9 m/s strikes a stationary eight ball of the same size and mass. After the collision, the queue ball’s final speed is 1 m/s. Find the queue ball’s angle with respect to its original line of motion. Answer in units of ◦. 2. Relevant equations I can't seem to figure out how you're supposed to get an angle for this, if none is given. 3. The attempt at a solution in 1-d the equation would be something like m1v1+m2v2=(m1+m2)*V. In 2-d, I assume you need a trig function, but how is that useful with no given angle?