hello guys ๐

i need your help with this problem

i need your help with this problem

i can understand that in (a) we will use the integral of row(v) * dv to get the charge

and in (b) we will use the formule D(r)=Q/[4*PI*r^2]

but in (C) should it be zero or what ??

and if it should be zero why in the solution manual it uses the formula of D(r)=Q[4*PI*(r^2)] again ?!!

i don’t know what is the right answer for this ..so i need your help ..Thanks guys ๐

http://ift.tt/1nnNFzj