Re: extinction6

["David Marjanovic" <david.marjanovic@gmx.at>]

> Collision types
>
> 1. Elastic: The difference of the sum of the kinetic energy of objects
> before and after the collision is zero.
>
> 2. Inelastic: A part of the sum of the kinetic energy converts to other
> form of energy during the collision.
> 2.1. Perfect inelastic: Velocities of objects are equal after the
collision
> therefore objects are moving together.
>
> You have it that this is happened when an extraterrestrial object collided
> with Earth.
>
> What is the proof? Why didn't fly away a part or the whole object with
less
> velocity?

You have forgotten gravity. It is easy to calculate that almost the entire
ejecta of the impact fell back to Earth within hours. In other words: The
impact was in the short run a normal inelastic collision, and in the long
run a perfect inelastic collision.