Originally Posted by **j-lee00** Correct. I want the equation to find the normal to a surface with Cartesian co-ordinates converted to spherical. I think there a particular formula but i cant find it. |

Well, you can do this in two ways.

First you can convert the equation for your surface into spherical coordinates then find $\displaystyle \nabla S(r,\theta, \phi)$

or you could find your normal $\displaystyle \nabla S(x, y, z)$ then convert that vector into spherical coordinates.

And what does this have to do with Motion and Forces?

-Dan