Two 72.0-kg hockey players skating at 7.00 m/s collide and stick together. If the angle between their initial directions was 130 degrees , what is their speed after the collision?

Answer 1

Use conservation of momentum in two perpendicular directions. Because of the equal speeds, the final direction will bisect the angle between the incoming vectors. You can write a single momentum equation along that direction, and solve for final speed Vfinal

2*72 * cos 65*7.00 m/s= 2*72 * Vfinal
Vfinal = 7.0 cos 65