A balloon is stuck to a straw with tape and the straw has a thread passing through it. The balloon's neck is tied with a thread.
i)Which direction does the balloon move when the thread tied to its neck is removed and why? ii)State the conclusion drawn from this activity.

Dear student,

When the thread on the neck of balloon is removed air escapes from mouth of balloon with great speed.So the reaction force acts on the balloon in opposite direction means left to right, as straw is attached to the balloon it moves on thread.
This activity demonstrated the third law of motion which is principle of jet propulsion and rocket propulsion.

Regards.