Question

why does a balloon stick to a ball after it its rubbed on polythene

Answer 1

Balloon stick to wall because of establishment of static electricity.

When we rub balloon against hair or sweater, the balloon will steal electrons from sweater, which leaves the sweater positively charged and the balloon negativity charged. The reason that the balloon will stick to the wall is because the negative charge in the balloon will make the electrons in the wall move to other side(because of like charge repel) and this leaves the surface of the wall positively charged. Because opposite charges attracts, the negatively charged balloon will be attracted to the positively charged surface of the wall.

Answer 2

because of static force when ballon is rubbed on hair it also stick