An object is projected into the air with a vertical velocity of 20 feet per second. At what times will the object be on the ground

20 ft/sec / 32 ft/sec^2 = .625     to reach top

2 * .625 = 1.25

It will be on the ground at t = 0 and t = 1.25

You can also solve the equation:

H = 0 = V0 t - 1/2 g t^2

Obviously, at t=0 h = 0

V0 = 1/2 g t    is a solution

t = 20 * 2 / 32 = 1.25 sec

gas and 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