Answer:
This shows that the balloon and the hair have opposite charges and that electric forces are non-contact forces.
Explanation:
We are told that the balloon, after having been rubbed on the hair, has excess electrons and hence is negative. Because of this, the hair has a shortage of electrons, which means that it is positively charged. Opposite charges attract. That is why when the balloon is brought close to the hair, the hair moves towards the balloon.
The balloon does not need to touch the hair to affect the hair because electrostatic forces are non contact, which means that they occur over "fields". They do not require the bodies in question to touch like push forces for example which are contact forces.
