Question #35864
1 Answer
But the rocket is not far from other objects. The rocket has fuel. And the fuel is the other object the rocket needs to change its momentum.
When the fuel burns in the rocket engine it is converted into a hot gas and pushed away from the main body of the rocket at high speed. When the gas is pushed away from the rocket, conservation of momentum tells us that the rocket gets pushed back with equal and opposite force. The total momentum of the rocket and the gas it has expelled must total to zero.
It is odd that this question is also concerned with uniform circular motion. This is true only if the rocket is in a circular orbit. In this case, gravity is constantly changing the direction of the rocket. In more elliptical orbits, the force of gravity is not so constant; weakening as you move farther from a massive object and getting stronger when you are near. This results in an elliptical orbit. Both the direction and velocity will change constantly under the influence of gravity.
