Differential Cartesian Coordinates Into Cylindrical Coordinates

sorter

Has to convert B6-1 into B6-2 Source Transport Phenomenon 2nd ed -

sorter

I can't even start solution
No idea how to convert subscipt from vx to vr and or to vtheta?????

arildno

You are to find the radial component of the transport equation.

Set up the relevant quantities and relationships, then we'll help you.

sorter

In the first equation: substitute Vx = Vr * Cos (theta) Vy = Vr * Sin (theta) Vz = Vz

but how do I get V(theta)