An inflated balloon was pressed against a wall after it had been rubbed with a piece of synthetic cloth. It was found that the balloon stuck to the wall. What force might be responsible for the attraction between the balloon and the wall?

Soln:

When an inflated balloon is rubbed with a piece of synthetic cloth, it becomes charged. A charged body attracts an uncharged body. When this charged balloon is pressed against a wall, it sticks to the wall. Thus, the electrostatic force acts between the charged balloon and the wall.