Acolumn of soldiers, marching at 121 steps per minute, keep in step with the beat of a drummer at the head of the column. it is observed that the soldiers in the rear end of the column are striding forward with the left foot when the drummer is advancing with the right. what is the approximate length of the column? (take the speed of sound to be 343 m/s.)

There’s a first “clump”/drum beat every half second. That clump will travel about 170m in half a second. Someone 170m away would do their “clump” as the second “clump” was taking place. I think.

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.

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