Two blocks are sliding on a frictionless table. One, with mass m, has a known velocity of magnitude v1 in the +x direction. The second, mass 2m, has a velocity that is at the known angle θ with the x axis and has unknown magnitude, call it v2. They collide and stick together and move away from the point of collision with a velocity which makes an angle A with the x axis. (a) What was the original velocity of the second block and (b) the magnitude of the final velocity?

Two blocks are sliding on a frictionless table. One, with mass m, has a known velocity of magnitude v1 in the +x direction. The second, mass 2m, has a velocity that is at the known angle θ with the x axis and has unknown magnitude, call it v2. They collide and stick together and move away from the point of collision with a velocity which makes an angle A with the x axis. (a) What was the original velocity of the second block and (b) the magnitude of the final velocity?