Answer:
The minimum thickness is [tex]t = 1.363 *10^{-7} \ m[/tex]
Explanation:
From the question we are told that
The index of refraction of the bubble is [tex]n = 1.33[/tex] = index of refraction of water
The wavelength is [tex]\lambda =725nm = 725 *10^{-9} \ m[/tex]
Generally the condition for constructive interference is mathematically represented as
[tex]2 * t = [m + \frac{1}{2} ] * \frac{\lambda }{n}[/tex]
Now t is the thickness and at minimum t, m(order of maximum ) = 0
So
[tex]2 * t = [0 + \frac{1}{2} ] * \frac{ 725 *10^{-9} }{ 1.33}[/tex]
=> [tex]t = 1.363 *10^{-7} \ m[/tex]
