A 12,500 kg railroad freight car travels on a level track at a speed of 5.2 m/s. It collides and couples with a 22,600 kg second car, initially at rest and with brakes released. What is the speed of the two cars after collision

Given :

A 12,500 kg railroad freight car travels on a level track at a speed of 5.2 m/s.

It collides and couples with a 22,600 kg second car, initially at rest and with brakes released.

To Find :

The speed of the two cars after collision.

Solution :

It is given that car couples with each other. So speed of both the cars after collision is same. Let, it be v.

Applying conservation of momentum, we get :

Therefore, the speed of the two cars after collision is 1.85 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.