Aball was 2.0 m off the ground and thrown horizontally. it traveled for 7.8 m before it hit the ground. what was the imitial speed of the ball

12 m/s

Explanation:

First, find the time it takes for the ball to fall 2.0 m.

y = y₀ + v₀ t + ½ at²

0 = 2.0 + (0) t + ½ (-9.8) t²

0 = 2 − 4.9t²

t = 0.639

Find the velocity needed to travel 7.8 m in that time.

x = x₀ + v₀ t + ½ at²

7.8 = 0 + v₀ (0.639) + ½ (0) (0.639)²

7.8 = 0.639 v₀

v₀ = 12.2

Rounded to two significant figures, the initial velocity is 12 m/s.

he . if i may ask what i your question exactly?

explanation:

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.