Aperson standing on a scale feels a normal force of 655 n pushing up on him. what is his mass? (unit=kg)

Approximately 66,8kg

Hope this help :D

Explanation:

F=mg. So 655N= 9.8 m/s² × mass.

Mass = 655 / 9.8

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.