Question

When you release the end of a full and untied balloon, what happens? Justify your answer with what you know about the physics of explosions? How does this relate to rockets?

Answer 1

When we release the end of a full and untied balloon, the air starts coming out of the end and according to the conservation of momentum, equal and opposite momentum is gained by the balloon in the forward direction. It is similar to rockets where the fuel comes out of the nozzle and the rocket goes up in the opposite direction.

Initial the momentum was zero. So the final momentum should also be zero in accordance with the conservation of momentum. That's why the balloon goes forward while the air coming out of the end of the balloon goes in the backward direction.