## University Physics with Modern Physics (14th Edition)

a. $m=\frac{E}{c^2}=\frac{1.0\times10^{20}J}{(3.00\times10^8m/s)^2}=1.11\times10^3 kg$ b. Find the volume V. $$\rho=\frac{m}{V}$$ $$V=\frac{m}{\rho}=\frac{1.11\times10^3 kg }{7860kg/m^3}=0.141m^3$$ Find the side length of a cube with this much volume. $$V=L^3$$ $$L=V^{1/3}=(0.141m^3)^{1/3}=0.521m$$