Today, we’re going to learn about how we can charge objects just by rubbing them together. Can anyone tell me what happens when you rub a plastic comb with dry hair?

Correct! When you rub them together, the comb gains a charge. This is known as charging by rubbing. Can anyone suggest why this happens?

Precisely! This brings us to the concept of static electricity—charges that stay in one place until something happens to release them. Remember: when similar charges are close to each other, they repel!

Exactly! That’s a great observation! Let’s collect more objects to see how they behave when charged.

Now let’s look at the types of materials we can rub and charge. If we were to rub a plastic refill with wool, what can we expect it to attract?

Correct! Based on the table we discussed, what happens if we rub two of the same kind, like two plastic refills?

Exactly! Remember, like charges repel each other while unlike charges attract. This is the foundation of understanding electric interactions.

Right! This difference explains why they attract each other. Keep this in mind!

Charges produced by rubbing can cause interesting effects. For instance, have you noticed your hair standing up when you take off a wool sweater?

That’s static electricity at work! The movement of charges in your hair is causing it to stand. Can anyone think of a situation where static electricity is useful?

Exactly! Laser printers use static to attract ink to the paper. Very good! Remember, every time you see those little sparks, it’s just static electricity doing its job!

No, but we must be careful and learn about how to handle it safely. That’s the key take-away!