An object at rest near the surface of a distant planet starts to fall freely. If the acceleration there is 4x that of the Earth, its speed two seconds later would be

50 inches should be the resultant vector

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.

there are no contact forces mentioned on the list of choices that you've provided.

technology is the application of the knowledge gained by science.