So this is based on the speed of the rocket. And the speed is also involved in what the weight of the rocket is and the force it has from the water. Because the mass and acceleration is being forced going up. The rocket needs enough force in order for it to take off. You can't have a huge mass and not enough force, because it will not work. And the third law of motion is, for every action there is always an opposite and equal reaction. So then when you have your rocket on the launch pad and all ready then its determining on the motion of the rocket being equal to and opposite from the nozzle. Like if the rocket goes one way and the water goes the other way. You want it to be centered and balanced. Figuring on how many times you have tested it will and can improve on your final launches. And then you will have a bigger idea on how the water being forced down is going to equal the force when the bottle goes
So this is based on the speed of the rocket. And the speed is also involved in what the weight of the rocket is and the force it has from the water. Because the mass and acceleration is being forced going up. The rocket needs enough force in order for it to take off. You can't have a huge mass and not enough force, because it will not work. And the third law of motion is, for every action there is always an opposite and equal reaction. So then when you have your rocket on the launch pad and all ready then its determining on the motion of the rocket being equal to and opposite from the nozzle. Like if the rocket goes one way and the water goes the other way. You want it to be centered and balanced. Figuring on how many times you have tested it will and can improve on your final launches. And then you will have a bigger idea on how the water being forced down is going to equal the force when the bottle goes