# Would an unwrapping tetherball be able to steal all earth momentum?

1. Oct 16, 2006

### giordano bruno

neglecting gravity in this problem the tetherball starts in the pole with a pole XD thickness of 1m

if the tether spins oposite to earth the earth pulls on the string a revolution every 24 hours accelerating the tetherball opposite sense

doesnt this agree with conservation of angular momentum?

i dont make any affirmation im just asking

2. Oct 16, 2006

### Staff: Mentor

The tetherball is accelerated toward the center pole, in a direction exactly perpendicular to its motion. Hence, it does not increase its speed linearly or increase its angular momentum. It doesn't affect the earth's angular momentum at all.

Last edited: Oct 16, 2006
3. Oct 16, 2006

### pervect

Staff Emeritus
Do a forum search for "tetherball". And please tell us that you are not eosphorous under a different name (but only if it's true, of course).

4. Oct 17, 2006

### giordano bruno

my point is that a tetherball APARENTLY breaks the conservation of angular momentum because it keeps a constant linear speed however the radius

after pages of discussion here its been agreed that the tether gets that extra angular momentum from earth

from there my idea to steal ertahs angular momentum

5. Oct 17, 2006

### Staff: Mentor

There is no such thing as "apparently" - it either does or it doesn't (hint: it doesn't).

Have you even tried to apply some math to calculate what happens here? We're not going to indulge your rambling rants. You need to show that you are willing to actually learn physics if you want these discussions to continue.

6. Oct 17, 2006

### Danger

Dang! You beat me to the 'Aviator Alert'. :grumpy: