A flat circular disc, of radius R, can be modeled as a thin disc of negligible thickness. It has a surface mass density function given by
f(r,phi)=k(1-(r^2)/R^2), where k is the surface density at the center and r is the distance from the center of the disc.
Using area integral in plane polar coordinates, calculate the total mass of the disc, in kg, when R=0.29m and k=25.02kgm^-2. Give your answer to 3 decimal places. Take pie as 3.142.