1.) The principles that Spectrum Ball is based on is force (more specifically acceleration) and the energy levels of different colors of light.
2.)Children will interact with the toy by playing common physical games such as soccer, volleyball, and kickball. The children playing with the Spectrum Ball will observe the differing colors displayed inside the ball (red-low intensity kick or hit- to violet -high intensity kick or hit-). The way in which the ball works is that there is an accelerometer suspended in the center of the ball that will measure the intensity of the blows to the Spectrum Ball. The higher the intensity, the higher level energy wavelength of light emitted.
3.) The cost for the Spectrum Ball will be relatively high. Due to the structural integrity of the accelerometer and suspension system. The durability of the ball will be good, but since the accelerometer/ suspension system has a certain level of fragility, the ball can only be subjected to reasonable conditions of force (i.e. human generated kicks and hits). The ball will be very safe because it has pressurized air inside, making the ball less rigid.