11. Each croquet ball in a set has a mass of 0.53kg. The gréen strikes the blue ball, which is at rest. Assuming that the balls slide on a frictionless surface and all collisions are head-on, find the final speed of the blue ball if the green ball continues moving after the collision at 2.5 m/s in the same direction.

11. Each croquet ball in a set has a mass of 0.53kg. The gréen strikes the blue ball, which is at rest. Assuming that the balls slide on a frictionless surface and all collisions are head-on, find the final speed of the blue ball if the green ball continues moving after the collision at 2.5 m/s in the same direction.