Dominic Roth is in a roller coaster car, which rapidly picks up speed as it rolls down a slope.
As it starts down the slope, its speed is 4 m/s. But 3 seconds later, at the bottom of the
slope, his speed is 22 m/s. What is its average acceleration?

6m/s²

Explanation:

Acceleration = change in velocity / time

Initial velocity = 4m/s

Final velocity = 22m/s

Time = 3s

Acceleration = (22 - 4) / 3

a = 18 / 3 = 6m/s²

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