How does the potential energy of the rising balloon increase?

As it rises, the ball “swaps places” with the air displaced by it. The mass of this air is greater than the mass of the ball (otherwise the ball would not rise). The potential energy of the sphere increases due to a decrease in the potential energy of the surrounding air, while the total potential energy of the Earth – sphere – air system decreases.
Answer: by reducing the potential energy of the surrounding air.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.