There are three Newton laws that apply to rocket science and basically everything. Newton's first law states that every object will remain at rest or in constant motion in a straight line unless required to change its state by the action of an outer force. In rocket testing, the rocket remains at rest until an unbalanced force (being the water acting as thrusters) allows the object to move by releasing pressure.
Newton’s second law states that the velocity (speed) of an object is altered when it is overwhelmed by an external force. In this case, the rocket’s speed is lessened as the water is being pushed out making the bottle is light which means the wind acts as the external force reducing its velocity. This can cause the rocket to stop as