Problem 5.146

There is a telescope whose objective has a diameter \(D\) \(=5.0 \mathrm{~cm} .\) Find the resolving power of the objective and the minimum separation between two points at a distance \(l=3.0 \mathrm{~km}\) from the telescope, which it can resolve (assume \(\lambda=0.55 \mu \mathrm{m}\) ).