# Lorentz Transformation Rapidity

1. Oct 25, 2012

### parsikoo

Concerning Rapidity, if tanh(Fi) = v/c, can it be concluded in general that the relative angle of two frames in combination with Lorentz Transformation is tan(theta) = tanh(Fi) = v/c, where theta is the relative angle?

2. Oct 25, 2012

### Fredrik

Staff Emeritus
What do you mean by the "relative angle"?

3. Oct 25, 2012

### robphy

Yes,
$\theta_{21} = \theta_{20}-\theta_{10}$.

4. Oct 29, 2012

### parsikoo

I meants relative angle of the frames.

5. Oct 29, 2012

### Fredrik

Staff Emeritus
That's what you said but what does it mean?

6. Oct 30, 2012

### parsikoo

Simply the math connection between rapidity and the angle of two frames, not sure if this is clear?