A stone is thrown upwards with an initial velocity of 25 m/s at an angle of 30^0 to the ground. Without any calculations, state what the stone's vertical velocity will be when it again reaches ground level.

Explanation:

The vertical component of the velocity of stone = 25 sin 30 = 12.5 m/s .

Horizontal component = 25 cos 30 = 21.65 m/s

After the throw , the body will go upwards with reducing velocity  and at top position , its velocity becomes zero . Again it comes down and its velocity gains . When it reaches the surface , it regains its earlier velocity which was in the beginning of the throw that is 25 sin30 but in downward direction .

So its vertical velocity when it reaches the ground will be 25 sin 30 = 12.5 m/s in downward direction.

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.