Answer:
The correct option is H
Explanation:
From the question we are told that
The index of refraction of coating is
The index of refraction of material is 
Generally the condition for constructive for a thin film interference is mathematically represented
![2 * t = [ m + \frac{1}{2}] \frac{\lambda}{n_1 }](https://tex.z-dn.net/?f=2%20%2A%20%20t%20%20%3D%20%5B%20m%20%20%2B%20%5Cfrac%7B1%7D%7B2%7D%5D%20%5Cfrac%7B%5Clambda%7D%7Bn_1%20%7D)
Here t represents the thickness
For minimum thickness m = 0
So

=> 
Answer:
62.5 %
Explanation:
Let the initial intensity of unpolarized light is Io.
After first polariser the intensity of light becomes I'.
So, 
Now it passes through another polariser. The angle between the first polariser and the second polariser is given by Ф. The intensity is I''.
According to the law of Malus

Here, Ф = 30 degree

The percentage change in the intensity is given by

= 62.5 %
She is traveling at a constant speed.