What do scientists use to determine the temperature of the star? a. therometer b. distance from earth c. composition d .color?

D. color

Explanation:

From Wien's displacement law: The peak wavelength emitted by the object is inversely proportional to its temperature. Thus, the spectrum of a star  is observed and its peak wavelength is measured. It is the color of the star. Temperature can be calculated:

A red color (longer wavelength) star would have low temperature than a blue star (shorter wavelength).

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