Turning stool
On the spinning stool you can experience forces from a spinning wheel either sitting or standing.
Spin the wheel using the wheel spinner or enlist the help of a friend who spins the wheel. With the wheel in your hands right in front of you, sit on the stool and put your feet on the footrest. Tilt the wheel to the side. Which way are you rotating? How do you rotate the other way? Examine what happens if you tilt the wheel more or less.
Try standing on the rotating plate with a spinning wheel. If the plate doesn't rotate the way you want, try moving around a little.
If one person is sitting on the stool and another is standing on the rotating plate, you can try to rotate in the same direction and at the same speed.
Nature has clever ways of dealing with forces in a way that may not always feel obvious or intuitive. One such field in physics is gyro forces.
The gyro wheel or gyroscope is a wheel that rotates on a shaft. This simple mechanism can behave in the most unexpected ways. When the wheel is stationary, it does not appear to have any special characteristics. If you put the wheel in the front fork of the Wheel balance experiment, it will fall to the side. If you attach the handle of the wheel to the hook in the Turning effect experiment, it will fall right down. A stationary wheel cannot defy gravity, but if the wheel is spun, everything changes!
When you spin the cycle wheel, it acquires other, exciting, characteristics. A wheel that spins around its own axis creates something called momentum. The characteristics of the momentum depend on the speed of rotation, the mass of the wheel and how the mass is distributed. In a bicycle wheel, for example, there is a larger part of the mass at the edge of the wheel. Therefore, it has a large momentum. Once the wheel is spun, it will effectively fight against any attempt to change the direction of the axis of rotation, something you experience as you explore the gyro experiments. When the bicycle wheel eventually comes to a standstill, it loses its gyro properties.
The gyroscope is used, among other things, to stabilise and navigate ships, aircraft, spaceships and other vehicles such as self-driving cars. A smartphone also has a built-in gyroscope to keep track of whether the phone is standing up or lying down. In healthcare, magnetic resonance imaging (MRI) of the rotating movement of your body's atoms is used to create images of the body's organs.
If you want to experiment more with gyro forces, you can do it with the aid of a yo-yo, frisbee and different types of spinners.
