Scientists are experimenting with a kind of gun that may eventually be used to fire payloads directly into orbit. In one test, this gun accelerates a 3.8-kg projectile from rest to a speed of 9.3 × 103 m/s. The net force accelerating the projectile is 9.3 × 105 N. How much time is required for the projectile to come up to speed?

Explanation:

Project mass m=3.8 kg

Initial speed vi= 0m/s

Final speed vf= 9.3×10³ m/s

Force F=9.3×10⁵N

To find

Time t

Solution

From Newtons second law we know that

∑F=ma

Where m is mass

a is acceleration

We can write this equation as

∑F=m(Δv/Δt)

Rearrange this equation to find time t

So

Substitute the given values

a.) travels faster in solids because the particles are closer together.

air is a gas water is a liquid

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.