Chapter 32 - Nuclear Physics and Nuclear Radiation - Problems and Conceptual Exercises - Page 1152: 8

(a) $3.3\times 10^{12}Kg$ (b) $1.8\times 10^{12}$ marbles

(a) We know that $m=\rho V$ We plug in the known values to obtain: $m=(2.3\times 10^{17})(\frac{4}{3}\pi (0.015)^3)=3.3\times 10^{12}Kg$ (b) We can find the required number of marbles as $N=\frac{M_E}{m}$ We plug in the known values to obtain: $N=\frac{5.97\times 10^{24}}{3.3\times 10^{12}}$ $N=1.8\times 10^{12}$