Conservation of angular momentum

The conservation of momentum, angular momentum, and energy are known as the three fundamental conservation laws in modern physics. The law of conservation of angular momentum is one of the universal laws in physics, which states that the angular momentum of a system remains constant when it is not subjected to external torque or when the external torque is zero. When the wheel rotates perpendicular to the ground, the chassis under the person's feet does not rotate. However, when torque is applied to the wheel to turn it horizontally, due to the conservation of angular momentum, the chassis will rotate in the opposite direction to the high-speed wheel to maintain the sum of angular momentum of the entire system at zero. Similarly, when the wheel is horizontally flipped, the chassis will reverse. The navigation device gyroscope installed on ships, airplanes, or rockets utilizes the principle of conservation of angular momentum.

The unit is designed for unsupervised public use: controls are recessed or shielded, moving parts are enclosed, and the interface is operable by a child of about six with no instruction. Where a screen is used, the language can be switched without changing the hardware, and the content can be replaced on site.