I calculated the equations for circlular motion as fallows...(adsbygoogle = window.adsbygoogle || []).push({});

[tex]

\vec{r}= p \hat{e_p} + z \hat{e_z}[/tex] where e_p = unit vector in the radial direction, and so on

[tex]

\frac{\partial{\vec{r}}}{\partial{t}} = \dot{p}\hat{e_p} + p\dot{\theta}\hat{e_{\theta}} + \dot{z}\hat{e_z} [/tex]

how do i show that the velocity is perpendicular to the radius, show me my mistake, but...

[tex] \vec{r} \bullet \vec{\dot{r}} = p \dot{p} + z \dot{z} [/tex] which isn't obvious to me that that is 0 so what to do?

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# Homework Help: Rotational motion

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