What is the speed of the air-track glider after the gun is fired? A light spring-gun projectile launcher is mounted on an 0.593 kg air track glider. The gun points upward at an angle of 27 o with the horizontal track. With the glider at rest, a 63.3- g projectile is fired from the gun with a speed of 2.79 m/s. What is the speed of the air-track glider after the gun is fired?