When an inflated balloon is released, it moves randomly due to a phenomenon known as Brownian motion or diffusion. Brownian motion is the random motion of particles suspended in a fluid (in this case, air) as they collide with the molecules of the fluid.
Here's an explanation of why the balloon moves randomly:
Air molecules: The air in the environment contains numerous molecules that are constantly in motion, colliding with each other and with objects around them.
Balloon surface: The surface of the balloon is elastic and contains a higher concentration of air molecules compared to the surrounding air.
Random collisions: As the balloon is released, the air molecules collide with the surface of the balloon, exerting a force on it. These collisions are random in nature, both in terms of direction and magnitude.
Newton's third law: According to Newton's third law of motion, for every action, there is an equal and opposite reaction. So, when the air molecules collide with the balloon, they exert a force on it, and in turn, the balloon exerts an equal and opposite force on the air molecules.
Resultant force: Due to the random nature of air molecule collisions, the resultant force on the balloon is not in a specific direction but rather varies with time.
Net movement: The random variation in the forces causes the balloon to move in different directions at different times. The cumulative effect of these random forces leads to the observed random motion of the balloon.
In summary, the random motion of the air molecules colliding with the balloon's surface causes it to move randomly when released, exhibiting Brownian motion.