A particle of mass moves under a force given bywhere and are unit vectors in the and directions. The particle is placed at the origin with an initial velocity After how much time will the particle first return to the origin

at positions a, g kinetic energy is maximum.

at position d, potential energy is maximum.

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.

reserve is the answer

explanation:

wheres the pic