# Weird looking version of angular velocity

1. Oct 17, 2007

### ylim

Hi there,

It is common that
angular velocity = radius * rate of change of degree over time,

angular vel = normal vector * rate of change of normal vector over time,

Can anyone please explain the correlation?

Thank you.

2. Oct 17, 2007

### Shooting Star

Very uncommon.

angular velocity = rate of change of angle over time
Linear speed=r*(dtheta/dt) on a circular path.

3. Oct 17, 2007

### ylim

Sorry. Yes, I meant angular velocity = rate of change of angle over time
but my concern is
angular vel = normal vector curl rate of change of normal vector over time,

4. Oct 17, 2007

### malty

No the second description isn't that uncommon. If you imagine measuring angular velocity in terms of the rate of change of the tangential velocity vector to the curve, and how the normal of this tangential vector curls in time when compared to the normal of this original vector for a given time interval $$\Delta t$$

[Will add a diagram in a few mins]
Hopefully that will clarify

Edit- Having serious trouble uploading diagram, (it's a bmp paint file but it exceeds the limit! :(

Last edited: Oct 17, 2007
5. Oct 17, 2007

### ylim

thankkssss..~ hmm, do you mind dropping me an email (the bmp) at wincluster@gmail.com

thank you.