Aspeed-time graph is shown below:

a speed versus time graph is shown with y-axis labeled position in centimeters per second up to 5 and x-axis labeled time in seconds up to 8. a straight line connects the points 0, 0 and 4, 4. a horizontal line connects points 4, 4 and 8, 4.

what is the average acceleration of the object represented in the graph above over the eight seconds?

0.5 cm/s2
1.0 cm/s2
1.5 cm/s2
2.0 cm/s2

Explanation:

Average acceleration is the variation of velocity over a specified period of time :

Where:

being the initial velocity and the final velocity  (according to the information given from the described graph)

Then:

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.