A horse is riding 9m/s. In two seconds it slows down to 1m/s, what is the acceleration of the horse.

-4m/s²

Explanation:

Given parameters:

Initial velocity  = 9m/s

Final velocity  = 1m/s

Time taken  = 2s

Unknown:

Acceleration  = ?

Solution:

The acceleration of a body is the change in velocity of a body with time.

    Acceleration  =

Insert the parameters and solve;

    Acceleration  =  = -4m/s²

We can say, the car is decelerating at a rate of 4m/s²

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.

i believe the answer is a hope it and is correct