High School Does more angular monentum mean faster spin?

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Angular momentum alone does not determine the speed of spin, as angular velocity is the key factor. The Earth has a higher angular momentum than a top, but this does not imply it spins faster due to differences in moment of inertia. For accurate comparisons, both objects must have the same mass and mass distribution. The relationship between angular momentum, moment of inertia, and angular velocity is crucial in understanding rotational motion. Therefore, without equal moment of inertia, conclusions about relative spin speed cannot be made.
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If a top has angular momentum of 12 units and the Earth has angular momentum of 100. Does this mean that Earth is spinning faster than the top since it has more angular momentum? The answer is there at the back of my head but can't articulate it.
 
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No. Angular velocity tells you what spins faster.
 
No. Angular momentum ( its magnitude) is the product of moment of inertia and the angular velocity. In your case the rotational inertia of the Earth and the top aren't equal, so you can't make the conclusion as you did.
 
Last edited:
Aniruddha@94 said:
No. Angular velocity ( its magnitude) is the product of moment of inertia and the angular velocity. In your case the rotational inertia of the Earth and the top aren't equal, so you can't make the conclusion as you did.

A typo, there, it's Angular Momentum that you meant.
 
sophiecentaur said:
A typo, there, it's Angular Momentum that you meant.
Aah yes, sorry.. I'll edit it. Thanks.
 
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As everyone else has said, the answer is no. You could only draw the conclusion you draw if the objects are the same (same mass and distribution of mass). To be more precise, the moment of inertia needs to be the same. I think you could draw this conclusion from other posts, but I just wanted to be explicit.
 
I do not have a good working knowledge of physics yet. I tried to piece this together but after researching this, I couldn’t figure out the correct laws of physics to combine to develop a formula to answer this question. Ex. 1 - A moving object impacts a static object at a constant velocity. Ex. 2 - A moving object impacts a static object at the same velocity but is accelerating at the moment of impact. Assuming the mass of the objects is the same and the velocity at the moment of impact...

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