Comet is seen after a long period of time. Why?​

Long-period comets have orbital periods longer than 200 years. ... Since it is the sublimation of these volatiles from the nucleus of the comet as it nears the Sun that gives rise to the coma and highly-visible tails, long-period comets have more material with which to put on a show.

Explanation:

a.) travels faster in solids because the particles are closer together.

air is a gas water is a liquid

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