I don't understand how an object in space can accelerate. Isn't space a vacuum and therefore there would be nothing to 'push' against (no mass) so how can a object such as a spaceship create any thrust when its not necessarily pushing against any matter?
2007-10-23 12:47:30 · 5 answers · asked by Jewlz 1 in Science & Mathematics ➔ Astronomy & Space
this is asked on here about every other day. it does need need any external matter to push against. The force of matter exiting a small hole rapidly is enough to push the container in the opposite direction. That's the "equal and opposite reaction".
2007-10-23 12:49:22 · answer #1 · answered by Anonymous · 1⤊ 0⤋
Dear Lady:
Please do not confuse the way things are here on the surface of the earth with the way things are in outer space. That is two different situations and some principles apply, others do not.
Now, in outer space you are not standing on a sheet of ice do not need to push against something to move forward or backward, etc.
So if you light off a rocket engine and it exhausts out the back of your space ship, then your space ship moves forward with an equal and opposite reaction. Find a chair with wheels on it that rolls well on a smooth floor. Sit in the chair in the center of a room, holding one or two heavy objects. Pick your feet up and "Throw the heavy objects across the room" to a friend.
If everything works right, you and the chair should be propelled away from your friend...EQUAL AND OPPOSITE
reaction...Law of Physics.
Okay???
2007-10-23 19:56:11 · answer #2 · answered by zahbudar 6 · 0⤊ 0⤋
The rocket pushes off from its own exhaust plume. Think of each molecule of exhaust as a tiny bullet. The rocket us pushed by the recoil of all those tiny bullets being fired out the engine nozzle at high speed. Each bullet pushes off from the rocket and the rocket pushes off from the bullets. It is Newton's 3rd law, for every action there is an equal and opposite reaction. Action is molecule being fired one way and reaction is rocket getting pushed the other way. Each recoil is extremely small, but they all add up. If this seems inefficient, it is. That is why rockets have to carry so much fuel and use it up so fast.
2007-10-23 19:51:13 · answer #3 · answered by campbelp2002 7 · 1⤊ 0⤋
In a rocket engine thecombustion gases expand and push in all directions. The gas that goes out the back doesn't do any good But the gas that is pushing forward makes the ship go.
2007-10-23 19:56:09 · answer #4 · answered by Renaissance Man 5 · 0⤊ 0⤋
Simply put:
The object "pushes" against the 'reaction mass`
of the fuel its rocket burns.
Push against a friend... you both move.
it's really just that simple.
2007-10-23 19:55:50 · answer #5 · answered by Irv S 7 · 0⤊ 0⤋