The visible spectrum of hydrogen can be described accurately with an empirical formula found by the swiss teacher johann balmer in 1885. this formula, which gives the wavelength of a spectral line as a function of an integer quantity n , describes the spectrum known as the balmer series. by varying n , you can calculate the wavelength of all spectral lines.
part a
find the minimum value of n in the balmer series for which the predicted wavelength is in the ultraviolet region of the spectrum.

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