How does the law of conservation of momentum apply to the motion of the rocket? (1 Viewer)

[sadpwner]

Is this sufficient to gain 2/2 marks?

While the rocket is launching, the burning fuel rapidly expels hot gases from the rear. The total momentum of the rocket is initially zero. At launch, the exhaust gases have momentum backwards, so the rocket must have an equal momentum forwards to conserve momentum.

 

[anomalousdecay]

Depends, but I would give that a 2/2. Also it gains momentum. Doesn't necessarily have to be equal in momentum (think of the scenario when using retro rockets!).

To make your answer a bit nicer, maybe instead of saying "exhaust gases have momentum backwards, so the rocket must have an equal momentum forwards to conserve momentum", I would say "exhaust gases have a momentum in the direction of expulsion, so the rocket gains a momentum equal in magnitude to the overall momentum of the exhaust gases, but opposing in direction of the exhaust gases, as a result of the law of conservation of momentum".

 

[Joshmosh2]

You can also include a brief diagram, including Frocket = -Fgases

 

[QZP]

I may be wrong, but I believe BOSTES would allocate one mark to stating the definition of the law of conservation of momentum.

 

[anomalousdecay]

I may be wrong, but I believe BOSTES would allocate one mark to stating the definition of the law of conservation of momentum.

Actually this would make sense too. As I said, it depends on a few things.