A 35 g steel ball is held by a ceiling-mounted electromagnet 3.6 mm above the floor. A compressed-air cannon sits on the floor, 4.6 mm to one side of the point directly under the ball. When a button is pressed, the ball drops and, simultaneously, the cannon fires a 25 g plastic ball. The two balls collide 1.4 mm above the floor.

Required:
What was the launch speed of the plastic ball?