Electric charge is distributed over the disk
x^2+y^2≤2 so that the charge density at (x,y) is σ(x,y)=17+x^2+y^2 coulombs per square meter.
Find the total charge on the disk.
For the following regions R and surface densities σ, find the total mass.
(a)R: 0≤y≤sin(pi x/L); 0≤x≤L; σ(x,y) =y.
(b) The region between the semicircles y=sqrt(1-x^2) and y=sqrt(4-x^2) and the segments of the x-axis joining them. The surface density is equal to the distance from any point to the origin.