What happens to an object's motion in each of the following cases? a. an unbalanced force acts on an object? b. two unequal forces act on an object in opposite directions? c. two equal forces act on an object in opposite directions?

a.

When an unbalanced force acts on an object, net force acts on the object and as a result of this net force , the object accelerates in the direction of the unbalanced force.

b.

When two unequal forces act on an object in opposite direction, there is net force on the object in the direction of the greater of the two forces. Hence the object accelerates in the direction of greater force.

c.

When two equal forces act on an object in opposite direction, they cancel out each other and there is no net force on the object . Hence the object does not accelerate.

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.