# Triple integral to find the gravity inside a solid sphere

1. Nov 4, 2008

gravity inside a solid sphere

1. The problem statement, all variables and given/known data
I'm having a hard time setting up a triple integral to find the force of gravity inside a solid sphere. I've done a similar proof in physics before with gravity inside a spherical shell, but it only required a single integral. In this problem the answer must be derived using a triple integral.

2. Relevant equations
Newton's law of gravity:

|$$\vec{F_{grav}}$$|= $$\frac{GmpdV}{r^{2}}$$

3. The attempt at a solution
I believe i found a way to set up the triple integral using spherical coordinates on another physics forum thread, but I don't understand how to get the integrand. Can someone please explain the way the intergrand was derived in the following integral?

Last edited: Nov 5, 2008