* Initial velocity of glider 1 (v1i): What is the speed and direction of glider 1 before the collision?
* Initial velocity of glider 2 (v2i): What is the speed and direction of glider 2 before the collision?
* Mass of glider 1 (m1): What is the mass of glider 1?
* Mass of glider 2 (m2): What is the mass of glider 2?
Once you provide these details, I can use the equations for a perfectly elastic collision to calculate the final velocity of glider 1.
