What is the constant density of a solid sphere given its radius and mass?

[etothey]

Homework Statement

The density of a solid sphere of radius R=10cm and mass M=15kg varies with distance from the center according to the equation p=po*e^(r/R). Determine the constant po.

Homework Equations

density= mass over volume.

The Attempt at a Solution

Change density to mass over volume. Set r = 0. Solve for po and get 3580kg/m3.
Apparantly the equation should be integrated, But I don't understand what the integration would give me?

 

[cupid.callin]

Hi etothey
(have a rho: ρ)


choose any spherical element of radius x and thickness dx
now write dm for this element in terms of its volume and ρ

integrate this eqn and find total mass M

now use ρ = M/V to find constant rho