The diameter of mars is 6794km, and its minimum distance from the earth is 5.58×10^7 km. when mars is at this distance, find the diameter of the image of mars formed by a spherical, concave, telescope mirror with a focal length of 1.95 m .

D = 0.2374 m

Explanation:

let D be the diameter of the image of mars, f be the focal length of the telescope mirror and β be the spatial resolution.

β = 6794×10^3/(5.58×10^7) = 0.1217562724

then:

The diameter of the telescope mirror is given by:

D = f×β

   = (1.95)×(0.1217562724)

   = 0.2374 m

Therefore, the diameter of the image of mars is 0.2374 m.