What will happen to the meteors and asteroids if these things hit the earth:
The meteors and asteroids, may break down into smaller pieces, when near earth, they can be incandescent due to the gravity of the earth.
What will happen to the earth if meteors and asteroids hit it:
It depends on that contact, if it is great, then there is a possibility that the earth can be destroyed, eruption of volcanoes, tidal waves, hydrogen sulfide (a toxic gas), and many other calamities and disasters may occur during, and after the impact when these things hit the earth.
~~ This will not happen, I'm sure. Just trust God :)