Aball of moist clay falls 19.3 m to the ground. it is in contact with the ground for 21.0 ms before stopping. (a) what is the average acceleration of the ball during the time it is in contact with the ground? (treat the ball as a particle.) (b) is the average acceleration up or down?

-926.67 m/s²

The negative sign indicates the direction is upward

Explanation:

t = Time taken

u = Initial velocity

v = Final velocity

s = Displacement

a = Acceleration due to gravity = 9.81 m/s² (positive downward and negative upward)

The ball will hit the ground at 19.46 m/s

The acceleration of the clay ball is -926.67 m/s²

The negative sign indicates the direction is upward.

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.