Complete Question
You stand on a straight desert road at night and observe a vehicle approaching. This vehicle is equipped with two small headlights that are 0.681 m apart. At what distance, in kilometres, are you marginally able to discern that there are two headlights rather than a single light source?Take the wavelength of the light to be 549 nm and your pupil diameter as 4.63 mm.
Answer:
The distance is
Explanation:
From the question we are told that
The is distance between the headlight is
The wavelength is
The pupil diameter is
Generally, we can mathematically evaluate the resolution of the eye as
substituting values
Now according to SOHCAHTOA rule
Where z is the distance at which the eye can discern the two head light
given that the angle is very small
=>
substituting values
=>
=>