Gravitational attraction of a cone

[alsinan1989]

Hello everyone,

I have been stuck on this geophysics question I have for one of my classes and I really need some help with it. Can anyone solve this question. If you do, please show me how because I am really stuck here. I am stuck on both a and b. Click the link below to see the question.

Thank You

http://i1142.photobucket.com/albums/n619/martin3100/Page1GeophysicsHW.jpg?t=1286671544

equations F= G [tex]\rho[/tex] v / r^2

i know that i have to use triple integrals but i don't know how to start

 

[jbsteele]

it. For part (a), set up the triple integral using cylindrical coordinates. The integral should be in terms of the variables ρ, θ, and z.The integral will be: ∫∫∫ Gρv/r² dρdθdz where G is the gravitational constant, ρ is the density of the ellipsoid, v is the volume, and r is the distance from the origin. For part (b), use a substitution to simplify the integral. To do this, you can substitute the variables x = ρsinθ and y = ρcosθ, which will reduce the integral to a double integral in terms of x and y. The integral will become: ∫∫ Gρv/r² dx dy where G is the gravitational constant, ρ is the density of the ellipsoid, v is the volume, and r is the distance from the origin.