A 1600 kg car moving south at 11.0 m/s collides with a 2700 kg car moving north. The cars stick together and move as a unit after the collision at a velocity of 5.08 m/s to the north.
A) Find the velocity of the 2700 kg car before the collision.

U = 14.61 m/s

Explanation:

Parameters given:

Mass of first car, m = 1600 kg

Initial velocity of first car, u = -11.0 m/s

(Taking the South as the negative y axis and the North as the positive y axis)

Mass of second car, M = 2700 kg

Initial velocity of second car, U is unknown

Final velocity of both cars, v = 5.08 m/s

To find the initial velocity of the first car, we apply the law of conservation of momentum:

Total initial momentum = Total final momentum

Inputting the values of m, M, u and v:

The initial velocity of the 2700 kg car is 14.61 m/s.

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.