5. A 2000 Kg truck travelling at 10 m/s towards North. collides with a truck with a mass of 3000kg which is stopped at the traffic light. After collision the two trucks stick together and move in the same direction. What is the final velocity of the two trucks which are
moving together after collision
MIVI+ M2V2i =(M1+ M2) Vf
5 m/s towards South
4 m/s towards North
4 m/s towards South
10 m/s towards North

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.

energy can be converted from one form to another, but it cannot be created or destroyed in ordinary chemical or physical means. do not understand what you are asking but hope this

i think the answer is a and b

i wish you luck