Consider a cylindrical shell so that the cross sectional radius is some constant a.(adsbygoogle = window.adsbygoogle || []).push({});

In the first term of the divergence expression in cylindrical coordinates:

[tex] \frac{1}{r}\frac{\partial}{\partial r}(rA_{r}) [/tex]

When I multiply the radial component byr, do I go ahead and substitute r=a before I take the derivative with respect to r or do I substitute r=a after I take the derivative with respect to r?

Thanks a lot.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Easy question about divergence in cylindrical coordinates

**Physics Forums | Science Articles, Homework Help, Discussion**