1. May 12, 2013

### rohit199622

when we need to find the direction of radial velocity should we move our right hand from the omega (angular frequency) vector to the radius vector ?or opposite ?

2. May 12, 2013

### Staff: Mentor

Radial velocity is always in the plane of motion and pointing directly towards or away from the center according to whether the distance from the center is increasing or decreasing. There's no right-hand rule involved; that only comes into play when you're calculating vector cross-products such as the angular momentum.

3. May 12, 2013

### WannabeNewton

I believe rohit is referring to the following equation from rigid body dynamics: $\mathbf{v} = \boldsymbol{\omega}\times \mathbf{r}$. In this case, if you want to use the right-hand rule, you would point your fingers in the direction of the angular velocity and curl them towards the position vector.

4. May 12, 2013

### Staff: Mentor

Ah - yes, that makes more sense. Thanks for the catch.

5. May 13, 2013

### rohit199622

thanks a lot !!