Question

Why does an air filled rubber balloon swing here and there when air escapes from the mouth of it.?​

Answer 1

If a balloon filled with compressed air and its mouth untied is released with its mouth in the downward direction, the balloon moves in the upward direction because the air present in the balloon rushes out in the downward direction. The equal and opposite reaction of downward going air pushes the balloon upwards.

Answer 2

Answer:

Because it is filled with Hydrogen Gas.

Explanation:

Hydrogen Gas is very light and the lightest gas in the air.