Answer:
0.71126 m
Explanation:
[tex]\lambda[/tex] = Wavelength = 550 nm
D = Lens diameter = 20 cm
L = Distance from object = 212 km
Angular resolution is given by
[tex]sin\theta=1.22\frac{\lambda}{D}[/tex]
[tex]sin\theta=\frac{d}{L}[/tex]
[tex]\frac{d}{L}=1.22\frac{\lambda}{D}\\\Rightarrow d=1.22\frac{\lambda\times L}{D} \\\Rightarrow d=1.22\times \frac{550\times 10^{-9}\times 212000}{20\times 10^{-2}}\\\Rightarrow d=0.71126\ m[/tex]
The separation of the two object on the Earth's surface is 0.71126 m