Answer:
39 m
Explanation:
We are given that
Wavelength=[tex]\lambda=400 nm=400\times 10^{-9} m[/tex]
1 nm=[tex]10^{-9} m[/tex]
y=1 km=[tex]1000 m[/tex]
1 km=1000 m
Earth mars distance =x=80 million Km=[tex]80\times 10^9 m[/tex]
1million km=[tex]10^9 m[/tex]
[tex]sin\theta=\frac{1.22\lambda}{d}[/tex]
[tex]sin\theta=\frac{y}{x}[/tex]
[tex]\frac{y}{x}=\frac{1.22\lambda}{d}[/tex]
[tex]\frac{1000}{80\times 10^9}=\frac{1.22\times 400\times 10^{-9}}{d}[/tex]
[tex]d=\frac{1.22\times 400\times 10^{-9}\times 80\times 10^9}{1000}[/tex]
[tex]d=39.04 m\approx 39 m[/tex]
Diameter of mirror =39 m
