Mi-1 Rotating Stool
Published: Thursday 09 March 2006 - Updated: Thursday 24 March 2011
To demonstrate the conservation of angular momentum.
- Rotating stool
- Dumbbell weight
- Bicycle wheel
Click on pictures to enlarge.
A volunteer student is seatd upon the stool holding a dumbbell weight in each hand close to the body. The stool is rotated slowly. The student then outstretches his/her arms and the redistribution of mass requires a change in rotational speed to conserve angular momentum.
If initially the student has his/her hands outstretched when the weights are brought in toward the body the increase in rotational speed can be large enough to make it almost impossible to stay seated.