If the masses of the earth and the sun were each multiplied by 3 without changing the distance between them, the gravitational force between the two bodies would be the present gravitational force between them.

Force will will become 9 times the previous value

Explanation:

Let the mass of earth is , mass of sun is and distance between them is R

From law of gravitation force between sun and earth is given by

, here G is gravitational constant

From the relation we can see that gravitational force is proportional to mass of them

And in question it is given that mass of both is multiplied by 3

So new force will be equal to

So force will will become 9 times the previous value

9 times

Explanation:

Let the mass of sun is Ms and the mass of earth is Me. The distance between them is R .

The gravitational force between the two is given by

As both the masses is multiplied by 3, and the distance between them remains same, then the force becomes 9 times.

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