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Angular momentum and the Ice skater

This demonstration illustrate conservation of angular momentum along the z-direction. Basically, the students observe how, by changing the moment of inertia of the system, the angular velocity is forced to change in order to conserve the initial angular momentum --the way ice skaters and divers control their rate of rotation. Typically this demo is a hands-on exercise for students in physics 121 lab. The implementation is done using a rotating platform with a stool fit to it. This demo requires a couple of 3 or 4 pound dumbbells. Recruit a volunteer and sit her/him on the stool and ask him to hold the dumbbells -one in each hand- close to the chest. Gently set the platform on an easy rotation. Starting with the smallest value of inertia (dumbbells close to chest) will only slow down the rider as she/he extends its arms away from the chest. If the rider can handle it, you can start her/him with the largest moment inertia --be careful.
ID: d0019
Set up time:
2 minutes in class.
Requires:
Notes:
You may need assistance the first time you use this demo.The platform does not have leveling screws, but it needs to be level. Hence, you may need to move it around to pick a good spot.You need a volunteer that is willing to get a bit dizzy.
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Documents:
Comments:

Table of Components

Qty. name location notes
1 Bicycle wheel with axis handles W106; Central Shelves;
1 PASCO rotating platform with stool W106; Central Shelves; U2-L1
1 Pair of dumbbells "
1 pair of Gloves W115; SouthWest Cabinet; U1;