Amazing apparatus consists of 5 urethane balls that become smaller from the top to the bottom in a ratio of 1:3. Such experiments as Collisions and the Law of Conservation of Momentum can be performed. By using core rod to hold the balls, the user raises the balls approximately 1 meter vertically from the floor and then drops them. The impact caused by collision of the bottom ball with the next 1 is transmitted eventually to the top ball, causing it to fly up in the air several meters. Includes 5 balls plus 1 extra ball with flag and chrome-plated rod.