# Circular Motion Eqns

1. Feb 7, 2006

### JohnSimpson

I'm curious, are there any known equations relating the period of a rotating object to the radius of rotation (presumably while under a constant applied force)

What about any relating the applied force to the period?

2. Feb 7, 2006

### stunner5000pt

there is a centripetal acceleration (the acceleration an object while it is moving in a circle, towards the center of the circle)
$$a_{c} = \frac{v^2}{r}$$
the velocity is distance (circumference of the circle) and the time is the period of one rotation
$$v = \frac{2 \pi r}{T}$$
then $$a_[c} = \frac{4 \pi^2 r}{T^2}$$

multiply acceration by force and taht gives the force period relation

3. Feb 7, 2006

### quasar987

multiply acceration by mass and taht gives the force period relation.

Good analysis stunner !

4. Feb 7, 2006

### stunner5000pt

WELL im no expert in this field... one can attest to that

5. Feb 7, 2006

### marlon

And what about the rigid rotators ?

marlon

6. Feb 9, 2006

### marlon

The given treatment only applies to point particles, not massive rotating objects (ie rigid rotators like a spinning sphere or rod)

Nope, he's not a scientist, he is a far greater genius. You certainly know him.

regards
marlon

7. Mar 9, 2006

### hypermonkey2

Mozart I believe.

Last edited: Mar 9, 2006