RGBall
Children can learn about the concept of Force through examining the dependence of light intensity and force in this ball. Because the force on the ball in the x,y, and z direction corresponds with the red, green, and blue LEDs respectively, the concept of vectors can be conveyed to children. One game they could play with this is trying to throw the ball in such a way that it produces a certain color. This will challenge, entertain, and keep children active.
This ball is made of a hard rubber to keep the electronic components safe and reduce impact injuries. It is also 4 inches in diameter to prevent choking.