A teacher bangs his ruler on his desk with a force of 15 N breaking it into pieces. If the ruler has a mass of 0.25 kg, how much force did the desk apply back to the ruler when it broke into pieces?

Well, this teacher is pretty dumb if you ask me.

Explanation:

5 N, i think this is right.

3.2x10^7

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.