# A rocket and a box

1. Jun 20, 2013

This is actually not a homework but it looks like one.So I posted here
1. The problem statement, all variables and given/known data
A rocket is pushing a box on empty space.
The rocket is exerting a force on the blue colored box.In turn the box is exerting the same force on the rocket.The engine(or fire or whatever) it exerting a force on the rocket..
2. Relevant equations

3. The attempt at a solution
At first the rocket gets close to the box,as it gets closer,the electromagnetic force builds up(the box starts to move) until the force from the engine and electro balance.The rocket moves at a constant velocity even closer to the box the electomagnetic force now exceeds the engine force and move at more acceleration.Again the rocket contacts and do the same.Will it keep bouncing like that if there were no energy loss?
And is my explanation right at the first place?

What would be a better explanation.I haven't studied such types of collision yet(or any types).So please be descriptive.

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2. Jun 20, 2013

### tiny-tim

sorry, i don't understand what the question is asking for

3. Jun 21, 2013

Just imagine that a person(Stationary) is observing a rocket driving a box across the empty space(No resistance forces.)
What Explanation could the observer give?
Is my explanation correct?

4. Jun 21, 2013

### SteamKing

Staff Emeritus
I doubt it. It doesn't make any sense.

5. Jun 21, 2013

### voko

If the box is not fixed "in space" in any way, it will be pushed by the rocket, with increasing velocity, till the rocket runs out of fuel. Then they will travel with some constant velocities, and the box will have a slightly greater velocity that the rocket. Why that is so is left as an exercise to the reader.

During the initial impact and shortly after, there will be oscillations in the box-rocket system. Also an exercise.

6. Jun 23, 2013

Yes this was what I was asking for.Sorry if it did not make any sense.
Why do you think the bouncing stops,because it(collistion)loses energy?

7. Jun 23, 2013

### CWatters

So in short you have an accelerating object (a rocket) colliding (elastically) with another object (the box).

As long as the collision is elastic then yes it will keep bouncing off.

Not sure what happens if the combination approaches the speed of light :-)

8. Jun 23, 2013

### voko

Yes.

9. Jun 24, 2013