code class$=$"asciimath"$>$Consider a homogeneous spherical piece of radioactive material of radius r$\_(0)=0\mathrm{.}04$m that is generating heat at a constant rate of g$=4\backslash$times $10^(7)($W$)/($m$^(3)).$ The heat generated is dissipated to the environment steadily. The outer surface of the sphere is maintained at a uniform temperature of $80\backslash$deg C and the thermal conductivity of the sphere is k$=15($W$)/($m$)*\backslash$deg Cb