Acart with mass 320 g moving on a frictionless linear air track at an initial speed of 1.8 m/s undergoes an elastic collision with an initially stationary cart of unknown mass. after the collision, the first cart continues in its original direction at 0.78 m/s. (a) what is the mass of the second cart? (b) what is its speed after impact? (c) what is the speed of the two-cart center of mass?

Part a)

m = 126.5 g

Part b)

v = 2.58 m/s

Part c)

v = 1.29 m/s

Explanation:

Part a)

By momentum conservation we will have

here we have

also since collision is elastic collision so we have

so now we have

Part b)

As we know that in perfect elastic collision we will have

now we will have

now we have

Part c)

Since there is no external force on it

so here velocity of center of mass will remain the same

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.

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.