It's that time of the week again.... PHYSICS TIME

[cirthix]

Everybody loves physics.... don't we?

A spherical capacitor has an inner sphere of radius R1 with a charge of +Q and an outer concentric sphere of radius R2 witha charge of -Q. Find the electric field and the eneergy density at any point in space. (b) Calculate the energy in the electrostatic field in a spherical shell of radius r, thickness dr, and volume of 4pir²dr between the conductors. (c) Integrate your expression from part (b) to find the total energy stored in the capacitor and compare your result with that obtained using u=.5QV

I'm kind of stuck on this one, hints please?

 

[Random Variable]

Find the electric field between R1 and R2 using Gauss's Law, and then integrate (epsilon naught)/2*E^2 over the volume.

 

[Random Variable]

4*Pi*r^2*E=Q/e

E^2 = Q^2/(16*Pi^2*r^4*e^2)

U = e/2?E^2*r^2*sin²?drdfd?

U = -Q^2/(2*Pi*e)*(1/R2-1/R1)

u=1/2(Q*V)
u= (1/2)*Q*[-Q/(4*Pi*e)(1/R2-1/R1)]