Consider a conducting sphere of radius R carrying a net chargeQ.
a). Using Gauss’s law in integral form and the equation |E| =σ/ε0 for conductors, nd the surface chargedensity on the sphere. Does your answer match what you expect? b).What is the electrostatic self energy of this sphere?
c). Assuming the sphere has a uniform density Ï, what is thegravitational self energy of the sphere? (That is, what amount ofgravitational energy is required/released when the sphere isassembled.) d). Assuming Q = 1 C and the sphere is made of ironÏ M= 7870 kg/m3, is there a radius R such that thegravitationalself-energy is just enough to overcome theelectrostatic self energy? If so, nd R.
