Euler's Disk is an educational toy known for a seemingly paradoxical dramatic speed-up in spin rate as the disk loses energy and approaches a stopped condition.
Euler's Disk
Euler's Disc Spins for Minutes
Credits: Vat19
Euler's Disc Laser Light Show
Credits: Vat19
The Maths of Spinning Coins and Euler's Disk
Credits: standupmaths
Matt & Hugh: The Euler Disk Which Spins Forever
Credits: standupmaths
Friction and Vibration
Note that Euler's Disk would spin & roll forever if it were not for friction and vibration.
Conservation of Energy
When Euler's Disk is spun, the disk contains both potential and kinetic energy. The potential energy is given to the disk when it is placed upright on its side. The kinetic energy is given to the disk when it is spun on the mirrored base.
Angular Momentum
Like a top, Euler's Disk uses its angular momentum to hold itself upright. As the disk spolls around in a circle it is held in place by a balance of the gravitational force pulling the disk down and the force applied by the mirror base which holds the disk up.
Credits: www.eulerdisk.com