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

The angular size of the object is $\theta=\frac{1.40\times10^8m}{4.3(9.461\times10^{15}m)}=3.44\times10^{-9}rad$. Use Rayleigh’s criterion to find the resolution. The resolving power is $\theta_{r}=1.22\frac{\lambda}{D}$. $$3.44\times10^{-9}rad =1.22\frac{\lambda}{ D}$$ $$D =1.22\frac{550\times10^{-9}m }{3.44\times10^{-9}rad }=195m$$