Hi
i am asked to use Gauss (div thm) to evaluate
double int over s of F=<x^3,0,0> dot ndS
where s is positive z hemisphere.
where i have to evaluate with the downward k normal vector.
so basically i did triple int of divF = triple int of 3x^2dV switch in spherical coord to finally end with -2pi/5 which i think is correct.
But my question is, how do i know if i get the downward or upward normal since i dont have any k comp ? Since it is negative, does it mean i already have it ?
thanks!
i am asked to use Gauss (div thm) to evaluate
double int over s of F=<x^3,0,0> dot ndS
where s is positive z hemisphere.
where i have to evaluate with the downward k normal vector.
so basically i did triple int of divF = triple int of 3x^2dV switch in spherical coord to finally end with -2pi/5 which i think is correct.
But my question is, how do i know if i get the downward or upward normal since i dont have any k comp ? Since it is negative, does it mean i already have it ?
thanks!