Our galaxy is classified as a(n)
a. irregular galaxy.
c. spherical galaxy.
b. elliptical galaxy.
d. spiral galaxy.

d. spiral galaxy.      

Explanation:

Our Galaxy is Milky Way Galaxy. It is classified as spiral galaxy due to its spiral shape. It contains a central bulge where stars are concentrated and a rotating flat disk. Spiral arms extend from the center of the galaxy. Halo surrounds the bulge and the disk and contains globular clusters.

Thus, option d is correct.

b. lifting dumbbell weight at 20-degree angle from the body after a 45-degree angle

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