Answer:
The minimum distance between two points on the  object that are barely resolved is 0.26 mm
The corresponding distance between the  image points = 0.0015 m
Explanation:
Given Â
focal length f = 50 mm and maximum aperture f>2
s = Â 9.0 m
aperture = 25 mm = 25 *10^-3 m
Sin a = 1.22 *wavelength /D Â
Substituting the given values, we get – Â
Sin a = 1.22 *600 *10^-9 m /25 *10^-3 m
Sin a = 2.93 * 10 ^-5 rad
Now Â
Y/9.0 m = 2.93 * 10 ^-5
Y = 2.64 *10^-4 m = 0.26 mm
Y’/50 *10^-3 = 2.93 * 10 ^-5 Â
Y’ = 0.0015 m