# mass of integral in spherical coordinates

• Mar 9th 2009, 09:19 PM
Frostking
mass of integral in spherical coordinates
I am suppose to find the mass of the solid region W given in spherical coordinates by

roe greater or = to 0 and less than or = 3
theta between 0 and 2 pi
phi greater than or = 0 and less than or == pi/4
The density is density(P) at any point P is given by the distance of P from the origin

I know that I set up a triple integral and multiply my function by roe^2 sin(phi) but how do I express my density at any point????

Thanks to all of you for all of your assistance this term! Frostking
• Mar 9th 2009, 09:23 PM
Chris L T521
Quote:

Originally Posted by Frostking
I am suppose to find the mass of the solid region W given in spherical coordinates by

roe greater or = to 0 and less than or = 3
theta between 0 and 2 pi
phi greater than or = 0 and less than or == pi/4
The density is density(P) at any point P is given by the distance of P from the origin

I know that I set up a triple integral and multiply my function by roe^2 sin(phi) but how do I express my density at any point????

Thanks to all of you for all of your assistance this term! Frostking

I believe the density function is just $\displaystyle \delta\!\left(\rho,\phi,\theta\right)=\rho$ since $\displaystyle \rho$ is the radial value (distance) of the point from the origin.
• Mar 10th 2009, 03:51 AM
HallsofIvy
By the way, $\displaystyle \rho$ is "rho", not "roe". "roe" is fish eggs!