# Does more angular monentum mean faster spin?

• B
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 cant articulate it.

## Answers and Replies

A.T.
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:
sophiecentaur
Gold Member
2020 Award
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.

A typo, there, it's Angular Momentum that you meant.
Aah yes, sorry.. I'll edit it. Thanks.

sophiecentaur
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.