Why can a balloon rubbed on dry hair stick to a neutral wall?
Show answer & explanation
Answer: Rubbing charges the balloon, which shifts charges in the wall and attracts it
Rubbing charges the balloon, which shifts charges in the wall and attracts it ✓ — Rubbing can transfer electrons from dry hair to a rubber balloon, leaving the balloon negatively charged. Its electric field slightly shifts charges in the wall, putting opposite charge closer to the balloon. That attraction can hold the balloon even though the wall as a whole remains neutral.
Rubbing removes the air between balloon and wall to make a suction seal — Rubbing does not create a sealed low-pressure pocket against the wall. A charged balloon attracts nearby neutral objects even before touching them, unlike a suction cup that needs a seal.
Rubbing makes glue that bonds the rubber to the wall — Rubbing hair and rubber does not create glue. It transfers electric charge, so the attraction does not require a sticky coating.
More Physics in Daily Life questions
- In a warm office that already reads 26 C, which change can make people feel cooler without lowering the thermostat?
- Why might 26 C feel acceptable in a breezy naturally ventilated summer building but too warm in a sealed winter office?
- On a warm, humid day, why can a 27 °C room feel worse once your skin is sweaty?
- Why can moving air make a 27 C room feel cooler without changing the thermometer?
- Why can a desk beside a cold window feel chilly even when the thermostat across the room still reads 22 C?
- Why might someone who just climbed stairs feel warm in a 22 C room while someone sitting in a T-shirt feels chilly?