Afilm of oil that has an index of refraction of 1.45 rests on an optically flat piece of glass of index of refraction n = 1.60. when illuminated with white light at normal incidence, light of wavelengths 642 nm and 428 nm is predominant in the reflected light.

determine the thickness of the oil film.

442.75862 nm

Explanation:

m = Order

n = Refractive index

= Wavelength

We have the relation of thickness and wavelength given by

The consecutive spectral line is given by

So,

and

Dividing the wavelengths we get

The film thickness of oil is 442.75862 nm

the force on the thing and the distance the force moves the thing

d₁ = displacement of tern from arctic to antarctic = 11000 miles

d₂ = displacement of tern from antarctic to arctic =   - 11000 miles

d = total displacement for the journey

total displacement for the journey is given as

d = d₁ + d₂

d = 11000 + (-11000)

d = 0 miles

t₁ = time of travel from arctic to antarctic = 3 months = 3 x 30 days = 90 days

t₂ = time of travel from antarctic to arctic = 3 months = 3 x 30 days = 90 days

t = total time of travel

total time of travel is given as

t = t₁ + t₂

t = 90 + 90

t = 180 days

average velocity is given as

average velocity = total displacement/ total time

v = d/t

v = 0/180

v = 0 miles/day