Use the Rayleigh criterion to estimate how far away (in km) you could be from the red taillights of a car and still distinguish them as separate lights. Assume that the lights are separated by 1.3 m, that the pupil is about 4.0 mm in diameter, that the wavelength is 650 nm, and that the intensity of the lights is sufficiently large that you can still see the car.

The value is  

Explanation:

From the question we are told that

     The separation between the light is  

    The diameter of the pupil is

    The wavelength is  

Generally from Rayleigh criterion can be mathematically represented as

Here r is the distance you could be from the red taillights of a car and still distinguish them as separate lights

 So  

=>    

the independent variable, or the one that is intentionally manipulated is the speed.