Action and reaction of a rocket in space.

In summary, the propelling force of a rocket is explained by Newton's 3rd Law of motion, where the action of ejecting gas results in an equal and opposite reaction on the rocket. This conversation highlights the importance of conservation of momentum in understanding the propulsion of a rocket.
  • #1
Clara Chung
304
14
By conversation of momentum, the rocket can be propelled forward by ejecting mass like gas.
However, how is the propelling force explained in terms of action and reaction? If gas is ejected, what does the force act on?
 
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  • #2
Clara Chung said:
If gas is ejected, what does the force act on?
The rocket.
 
  • #3
Clara Chung said:
By conversation of momentum, the rocket can be propelled forward by ejecting mass like gas. However, how is the propelling force explained in terms of action and reaction?
Conversation of momentum is ensured by Newton's 3rd Law (action and reaction).
 
  • #4
Clara Chung said:
If gas is ejected, what does the force act on?

Russ already answered this, but think for a moment. What's acting on the gas to eject it? Where's that force coming from? If the combustion process inside the engine creates a high speed gas, what forces it to go one way instead of expanding outwards in all directions?
 

1. How does a rocket move in space?

A rocket moves in space by expelling hot gas from its engines in one direction, which propels the rocket in the opposite direction, following Newton's Third Law of motion - for every action, there is an equal and opposite reaction.

2. Can a rocket still move in space without air?

Yes, a rocket can still move in space without air because it carries its own fuel and oxidizer, which are used to generate the hot gas needed for propulsion. This allows the rocket to move and change direction in the vacuum of space.

3. How do the forces of thrust and gravity affect a rocket in space?

The force of thrust from the rocket's engines propels it forward, while the force of gravity pulls it towards the center of a larger body, such as a planet or moon. These forces have to be balanced for a rocket to maintain a stable orbit or trajectory in space.

4. Do rockets need to constantly fire their engines to stay in space?

No, rockets do not need to constantly fire their engines to stay in space. Once a rocket reaches its desired speed and trajectory, it can coast through space without using its engines. However, small adjustments may need to be made periodically to maintain its course.

5. How does a rocket change direction in space?

A rocket can change direction in space by using its thrusters, which are smaller engines that can be fired in different directions to adjust its trajectory. This can be done by changing the angle of the thrusters or by using a combination of different thrusters to create a specific direction of thrust.

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