A 0.6 kg ball is initially at rest on a frictionless, horizontal surface. It is struck by a 0.4 kg ball initially moving with a velocity of 0.25 m/s toward the right along the x-axis. After the collision, the 0.4 kg ball has a velocity of 0.2 m/s at an angle of 36.9° above the x-axis in the first quadrant. What is the magnitude of the velocity of the 0.6 kg ball after the collision?