Answer to Question #94483 in Physics for Athulya

Question

How a baloon toy with air and water returns back if we push that toy on a particular side?

Answer 1

Do you mean that you fill the balloon with water? If you mean elastic deformation when the balloon returns to its initial shape, it's simple: the walls are made of flexible rubber. Water can be considered as incompressible fluid, so all force you apply to the balloon transfers to the water. According to Pascal's law, the pressure is transferred to all directions. That change of pressure causes the sides of the balloon to bend, and since they are flexible, it returns back to its initial shape.

If you "kick" such a balloon and notice that it slightly returns back, it is because of momentum conservation: you push the balloon. The pressure transfers to all directions, especially to the counter side. Then the side deforms back and gives motion to water, balloon returns back. And do not forget about the friction between the water molecules and sides of the balloon.