Amerry-go-round is a common piece of playground equipment. a 3.0-m-diameter merry-go-round, which can be modeled as a disk with a mass of 290 kg , is spinning at 25 rpm. john runs tangent to the merry-go-round at 5.6 m/s, in the same direction that it is turning, and jumps onto the outer edge. john's mass is 30 kg.

Answer

given,  

diameter of merry - go - round = 3 m  

mass of the disk = 290 kg  

speed of the merry- go-round = 25 rpm  

speed = 5.6 m/s  

mass of John = 30 kg  

initial angular momentum of the system  

final angular momentum of the system  

from conservation of angular momentum  

neither accurate nor precise.

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.