Hypotesis: If a space ship is at rest in space, and then turn it´s engine on, would it move?

Question

Ok, if the ship is at rest in perfect vacuum, would it´s engine when on cause any restistance to the surroundings as to provoke a "push" reaction causing it to move? (Newton)

Answer 1

Yes. The thing is - an engine works because of one of Newton's laws of motion. For every action there is an equal and opposite reaction.

A rocket engine expells a force out behind it as it ejects some of its mass. Force = Mass * Velocity. The more mass ejected and the higher velocity it is ejected, the more force created. This force is then reflected against the vehicle, and depending on how much mass the vehicle has, it will begin to accellerate at a certain rate.

Now if you were to take a regular propeller driven craft in space, you would not move with the propeller spinning. There is no air for the propeller to move. (well - actually there is a very very very tiny amount, so you WOULD move, but not anything measurable).

The real trick behind engines in space - is getting a reaction to occur without oxygen (or else by bringing your own oxygen along). Thats why they came up with ion engines. Instead of using an explosion or something that is designed to move air, this uses electricity to create a steady stream of ionized particles that will be expelled from the ship. And since there is little resistance in space, the tiny ions are enough to move the huge space crafts.

Answer 2

Well just turning your engines on does not produce thrust. If the thrusters were engaged then yes the ship would move. The laws of physics apply in space too. For every action there is an equal and opposite reaction. The thrust would propel the ship forward from the force that it produced in th eopposite direction. Also if the ship never engaged retro thrust to counteract the forward momentum, then it would travel in that direction forever. Nothing in space to slow it down that is if you didn't hit a meteor or planet in the process. LOL

Answer 3

Rockets don't push against anything. They move because of Newton's third law. The force of the gasses flowing out the engine act in an opposite way on the rocket. It's like you standing on ice and throwing a bowling ball forward. You will slide backwards.

Answer 4

Of course it would move, if it didn't we would never be able to travel through space at all. All rocket powered probes, satellites and manned spacecraft have turned on engines during their flights and they work just fine. The engine's thrust does have something to push against, it's called the spacecraft. Newton's law is quite safe.

Answer 5

yes, it will. Because of the thrust of the engine, it'll go at the same direction forever until the thrust is reversed, until then the ship should try to dodge asteroids, meteors, and planets LOL

Answer 6

yep, it'd move. there's not resistance in space. any little tug or push would move you. so if that were possible, it would move.

because you would have to be away from other galaxies to stay perfeclt still, you'll never know if you're moving. you'll never have the chance to be perfectly still in space because like i said, there's no resistance. if one galazy is too close, it's gravity would pull you. so there is no way of really telling wheather you're moving or not.

Answer 7

I'll let you in on a little secret; it works and we've been doing it for almost 50 years dude. It does not need to "push" against anything; go hit the physics books again slugger.

Answer 8

if the propulsion system could operate in a vacum, then yes. because the force is in the expulsion, and does not need resistance. Now lemme get back to my beer.

Answer 9

Yes it pushes against itself.

Answer 10

Not sure, let me go try it out and get back to you.