Derivative of the flight path angle

[Dustinsfl]

Why is this true?
$$
h = rv_{\perp} = r(r\dot{\nu})\Rightarrow\dot{\nu} = \frac{h}{r^2}
$$
Look at the last page http://www.mathhelpboards.com/f49/orbital-mechanics-notes-3682/#post16317 to see a visualization.

 

[chisigma]

Why is this true?
$$
h = rv_{\perp} = r(r\dot{\nu})\Rightarrow\dot{\nu} = \frac{h}{r^2}
$$
Look at the last page http://www.mathhelpboards.com/f49/orbital-mechanics-notes-3682/#post16317 to see a visualization.

If $\displaystyle v_{\perp}$ is the radial speed is $\displaystyle v_{\perp}= r\ \dot{\nu}$ where $\nu$ is the angle in radians...

Kind regards

$\chi$ $\sigma$

 

[Dustinsfl]

If $\displaystyle v_{\perp}$ is the radial speed is $\displaystyle v_{\perp}= r\ \dot{\nu}$ where $\nu$ is the angle in radians...

Kind regards

$\chi$ $\sigma$

Wouldn't $v_{\perp}$ be the tangential speed? $v_r$ I would think is the radial speed.