# $F_n$ force between 2 objects in space

I am trying to do a research project for school where I'm trying to simulate the physical world in a computer environment. So far things have been working great but I have trouble understanding how does the fn force or the normal force work on "floating objects". I understand that the fn force is equal to the opposite force which is working on an object. But what happens when the 2 objects are in space for eg. if we have a rocket with an acceleration of 5 colliding with an asteroid what is the fn of the asteroid on the rocket. Also, how do we know what is the max fn an object (let's say an elevator/lift) can have before the ground brakes? If the fn of the asteroid is equal to the force of the rocket does that mean that after the collision there is no more acceleration? That definitely isn't the case right? I hope someone can help me out, thanks in advanced.

• Welcome to physics SE. You will need to rethink the subject. You will find that energy and momentum are the crucial things for guessing what happens after the collision. It would be like with billiard balls. I see you do not need to consider gravitation, which is good for you. – jaromrax Jan 23 '19 at 12:38
• @jaromrax This is only true if the spaceship is not pushing the asteroid and causing both of them to gradually accelerate. More context is needed. – probably_someone Jan 23 '19 at 12:43
• The truth is that I dont understand fully your question. But if there is a collision - you need momentum/energy conservation. For a thrust - a simple acceleration generated to a rocket with mass $m$ you need to recalculate for $M_{asteroid}+m$. You (may?) need to know that the force is a derivative of momentum and also ciolkowski equations, but I have no idea about the task level. – jaromrax Jan 23 '19 at 13:34