Final answer:
Increasing force on a balloon leads to higher internal pressure and potentially bursting the balloon according to Boyle's Law. Releasing a balloon filled with air shows propulsion due to Newton's third law, but with water, propulsion effects differ.
Step-by-step explanation:
If the amount of force applied to a balloon on the end of a string keeps increasing, the likely outcome is that the balloon will burst. This is because as the force increases, the pressure exerted by the gas particles inside the balloon increases as well. According to Boyle's Law, the pressure and volume of a gas at constant temperature are inversely related. As a weather balloon rises and the atmospheric pressure decreases, it expands; when the tension from the expansion exceeds the balloon's elastic limit, it will eventually pop.
In the scenario you described, which sounds somewhat like a Take-Home Experiment-Propulsion of a Balloon, if the balloon is filled with air and let go, the air will rush out and the balloon will be propelled in the opposite direction, illustrating Newton's third law of motion: for every action, there is an equal and opposite reaction. However, if the balloon is filled with water, it likely won't propel in a similar manner due to the water's resistance to rapid expulsion and different aerodynamic properties. This demonstrates a simple propulsion system where the direction of the expelled air/water influences the direction in which the balloon moves.