Late one night on a highway, a car speeds by you and fades into the distance. Under these conditions the pupils of your eyes (average refractive index = 1.36) have diameters of about 7.0 mm. The taillights of this car are separated by a distance of 1.4 m and emit red light (wavelength = 660 nm in vacuum). How far away from you is this car when its taillights appear to merge into a single spot of light because of the effects of diffraction?
By the Rayleigh criterion minimum angle that can be resolved=theta is found out by
Sin theta = 1.22 lambda ...
Calculates the distance at which the taillights of a car appear to merge into a single spot of light because of the effects of diffraction.