$(a)\;\large\frac{\rho_{0} R}{9 \in_{0}}\qquad(b)\;\large\frac{\rho_{0} R}{12 \in_{0}}\qquad(c)\;\large\frac{\rho_{0} R}{3 \in_{0}}\qquad(d)\;\large\frac{\rho_{0} R}{6 \in_{0}}$
