10) if the mass 2m, the left mass
is m/2 and the distance is
r what is the gravitation
force ?

F = .

Explanation:

Gravitational force between two objects of masses kept at a distance r is given by the formula

F =

Here , = 2m

          =

Thus , F =

          F = .

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.