Which form of the law of conservation of energy describes the motion of the block when it slides from the top of the table to the bottom of the ramp?

By definition we have that the energy at the top of the ramp is equal to the energy at the bottom of the ramp. This is due to the principle of energy conservation.

We have then:

The energy at the top is only potential energy:

Where,

The energy when it falls is transformed into kinetic energy and therefore:

Where,

Therefore we have:

The potential energy is transformed into kinetic energy.

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