Explain how your weight can change even though your mass remains the same.

See explanation below

Explanation:

Recall that Weight is a Force that results from the action of a gravitational field on our body mass. Therefore if one changes locations to places where the acceleration of gravity is different, our weight can change although the mass of our body stays the same.

For example, going to a high mountain, where the acceleration of gravity is a little smaller than at sea level, will produce such change. Also, going to another planet with different gravitational field, or going to the Moon (where the acceleration of gravity is about 1/6 of that on Earth which therefore will reduce our weight without reducing our mass)

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.

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.