In polar-cylindrical coordinates, what is horizontal velocity?

Question

theeric · Answer

Hello! If you're using polar as like...

theeric · Answer

$x$ is horizontal and $y$ is vertical...

anonymous · Answer

in polar u use, r, theta

theeric · Answer

And instead you're using $r$ and $\theta$...|dw:1376244337612:dw|

theeric · Answer

@Mashy :)

theeric · Answer

So, @gorica , what do you have to do to find the horizontal part? Any ideas? It'll be good practice to try to think about this, but I'm sure @Mashy and I can help you get there if you're not sure!

anonymous · Answer

well m  sure u alone can handle it :P.. so m out :D

gorica · Answer

I have position vector $$\vec r=r \vec {e_r}+z \vec {e_z}$$
and I have velocity vector
$$\dot {\vec r}=\dot r \vec {e_r}+r \dot  \theta \vec {e_\theta}+\dot z \vec {e_z}$$

theeric · Answer

Oh, gosh, more complicated than I thought. @Mashy , please check this out when you come back on!

theeric · Answer

I messaged a person who might be able to understand that.

gorica · Answer

|dw:1376245533310:dw|