Have you ever gotten a shock when you touched a metal doorknob? Have your socks stuck to your shirts when you took them out of a dryer? These are examples of static electricity! You can use static electricity to roll a can without touching it in this fun experiment!
What to get:
- A piece of PVC pipe about 2 feet (60 cm) long
- A dry washcloth
- An empty soda can
What To do:
- Rub the cloth up and down the PVC pipe for about 30 seconds, until you can hear the crackle of static electricity.
- Place the soda can on its side on a level countertop.
- Move the pipe toward the can and see what happens.
The science behind the experiment:
Static electricity is electricity that gathers in one place, rather than flowing between places. Static means “unmoving”.
When electrons move from one atom to another, they create an imbalance in electrical charge: one material has extra electrons, making it negatively charged, while the other is missing some electrons, giving it a positive charge. In an effort to restore balance, atoms with too few electrons are attracted to those with too many. Similarly, atoms with too many electrons will try to move away from one another, as will those with too few. In other words, opposite charges attract, while identical charges repel, leading to some fascinating phenomena.
The soda can is positively charged. When you bring the negatively charged PVC pipe close, the opposites charges attract and the can moves toward the pipe. You are able to roll a can without touching it!
Scientists ask questions:
- What happens if you rub the pipe longer to build up a stronger charge?
- How fast can you get the can to move across the countertop?