A spaceship is at rest at point A in empty space. By using its rocket engines, it travels to point B.?

Question

How is this possible, since a body cannot change its momentum by using only internal forces?

Answer 1

Rockets emit gases at very high velocities. The momentum imparted to the ship is equal and opposite to the momentum of the exiting gas particles.

Answer 2

You were right by saying a body can not change its momentum by INTERNAL forces. But the fuel being ejected out of the rear is being pushed out by the spaceship but by Newton's third law the fuel also applies a force to the spaceship so it moves. Hope this helped.

Answer 3

Remember, for every action, there is a reaction.
Firing the engines causes an action which upsets the state of rest and causes a reaction -- the movement of the rocket in space in a direction opposite the direction of the engine exhaust..

Answer 4

Rockets throw of exhaust gases at extreme high speeds. The center of gravity of the entire system ( rocket and exhaust gas ) stays at the same location. Total momentum stays constant.

Answer 5

who said a rocket engine is an internal force? it simple newtonian physics, for every action the is an equal and opposite reaction. The rocket engine releases gas in one direction , causing the rocket to move in the opposite direction.

Answer 6

Because it uses external forces. Namely, it throws the rocket exhaust out from its engines. The exhaust momentum then becomes external.

Answer 7

Rocket engines work by creating expanding gasses. These gasses push against the rocket, and in turn push themselves out of the rocket. Since the rocket's gasses push against the rocket before LEAVING, they force the rocket in the direction that they are pushing.

Answer 8

Hi. The forces just have to balance. If you were in the same place and threw a rock, the rock would go one way and you would go the other. The total momentum is unchanged.

Answer 9

you are able to define "the physique" as being any device of goods. So, there are 2 hassle-free strategies to ascertain it. way a million: define the rocket gas as component of "the physique." hence, the excellent momentum of "the physique" does not substitute! One component of the physique (specifically the deliver) scoots off from A to B; on an analogous time as the different component of "the physique" (the exhaust products of the gas) shoot off interior the different direction. once you upload up the excellent momentum of the two aspects, you will see that this is nonetheless 0, and that the middle of mass of the excellent device continues to be at factor A. way 2: define the rocket gas as not being component of "the physique." hence, the rigidity in not inner! somewhat, there is rigidity from an "exterior" agent (specifically the increasing gas of the gas) pushing against the forward component of the engine, and making use of "the physique" (in simple terms the deliver) forward.

Answer 10

Of course it can, its engines produce thrust which propels it in any given direction.