Angular Momentum - Science Theater 24

Ice skaters spin faster by hugging themselves tight, but what does that have to do with riding a bicycle? In both cases, the law of conservation of angular momentum is in effect. Watch a few more angular momentum examples!

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Category:

Education

Tags:

• science
• physics
• momentum
• angular
• demonstration
• education
• k-12
• experiment

[nanoload]

Great demonstration. Only one thing: the reason that if you pull back and release two balls two would be moving from the other side relies not only on the law of conservation of momentum, but also the law of conservation of energy. Only when the other object has the same kinetic energy and the same momentum, it would have the same velocity and mass, other wise it could have doubled velocity (and there for quadrupled kinetic energy) and half of the mass - which is one ball.

[sciencetheater]

@nanoload Very astute. Yes, it relies on both, but I didn't want to get into conservation of energy at this time. One lesson at a time! (Of course, if either law didn't work, the demo would fail, so I'm just explaining part of the situation, and not spreading false information. It is common in science education to build up slowly and explain only the topic at hand... ignoring friction at first, for instance...)

[DracoMhuuh]

Why havent your tried stepping on the platform and asking someone to give you the spinning wheel? Normally it would have worked better. I think the platform might have been spinning slowly when you stepped on it thus the starting amount of angular momentum was not 0 on the vertical axis. Which might explain why it didn't reverse direction when your reversed the wheel. Anyways great video

[sciencetheater]

@DracoMhuuh Probably because I'm mostly a one-man show.  If I don't list is otherwise, I'm the only one in the room. (About half the episodes I had one cameraman helping out...)

[boumbh]

You're failure fighting the angar mentum was so funny (good self mockery of yours). I had hard time thinking of the reason of this failure. I can only think of friction on the wheel axe... Maybe using a wheel with less friction and/or a greater moment of inertia? Did you find the reason / try this experience again since?

[sciencetheater]

@boumbh I didn't redo it, although I tried a couple "takes" of it that day. I suspect I had a tad bit of momentum when I stepped on and thus only could go "one way"...

[sciencetheater]

I like em... I have a closet full of them...

[HavazikFerric]

Oi bowties are cool...

[clairebehun]

really informative and interesting

[rodswebdesign]

you have some great stuff here

[redrot1]

this is Y it didn't work

watch?v=JtCoa3jDP7g

[sciencetheater]

@acebodine Not really sure, Acebodine... I thought Coriolis had more to do with the earth's rotation specifically...