yego.me
💡 Stop wasting time. Read Youtube instead of watch. Download Chrome Extension

Electric forces | Forces at a distance | Middle school physics | Khan Academy


2m read
·Nov 10, 2024

Have you ever taken a shirt out of a dryer and found a sock stuck to it? If you have, you might have noticed that once you pull the sock off, it was still attracted to the shirt, even when they weren't touching. What is even happening here? Well, it turns out there's an electric force between the shirt and the sock.

Electric forces are a type of non-contact force, which means they can act on objects that aren't even touching. If you've ever noticed two balloons repelling each other, or if you've ever noticed your hair sticking to something like a balloon or a sweater, that's what I'm talking about.

But why is there an electric force between the shirt and the sock after they're taken out of the dryer? Well, it turns out that electric forces are caused by a property of matter called electric charge. Matter is made up of tiny particles that can have positive, negative, or neutral charge. Neutral just means that the electric charge is zero, not positive or negative.

When you add up all these charges, most objects tend to have a net charge that is about neutral; otherwise, we'd be attracted to all sorts of things, just like that sock. However, an object's charge can change. So, in the dryer, all that heat and movement allowed some negative charges from the shirt to move to the sock.

Now, when you try to separate the two, they are both electrically charged, and there's an electric force between them. So now that we know what causes an electric force, let's look at what affects its direction and strength.

An electric force can attract or repel an object, but how do you know if an electric force will be attractive or repulsive? Well, as the saying goes, "Opposites Attract." An object with a negative electric charge will be attracted to a positively charged object. If the second object is also negatively charged, well, the two objects will experience a repulsive force and be repelled from each other.

So, in order to have the sock and the shirt attracted to each other, they must have opposite net charges because they're experiencing an attractive electric force. What about the strength of that electric force? Strength will depend on a couple of factors.

First, the charge of each object is proportional to the force. The stronger the charge is, the stronger the electric force. So, the greater the electric charge, the greater the electric force. Another factor is how far apart the objects are from each other. The electric force will weaken as the distance increases.

So, the force decreases as our distance increases. As you move the sock away from the shirt, eventually the attraction between them is so weak that we don't even notice it. So, the next time you find yourself doing laundry and having to pull a sock off of a shirt, just remember, invisible electric forces are to blame.

More Articles

View All
Private jet expert destroys noobs
What celebrity owns the most expensive private jet in the world? Oh man, so there’s two people ahead of this guy, but you don’t know them and I don’t know them. One is Sultan of Brunei, $22 million. Okay, Sultan of Brunei was from like 20 years ago. This …
Hyena Skulls and Suspicious Batteries | To Catch a Smuggler: South Pacific | National Geographic
At Oakland’s International Mail Center, Customs officers routinely scrutinize mail from many countries. Today, Customs Officer Naomi is taking a closer look at a package sent from Kenya. It’s declared as head lamps; this is the x-ray image of the package,…
Interpretting exponential expression
The expression ( 5 * 2^T ) gives the number of leaves in a plant as a function of the number of weeks since it was planted. What does two represent in this expression? So pause this video and see if you can figure it out on your own. All right, so let’s …
This one thing happens when you own a private jet...
Whatever you think you’re going to use when you own a plane, you will do it 50 to 80% more when you have that airplane. Cuz it’s just the ease of just calling up and saying, “I want to go tomorrow to such and such a place, and we’ll come back tomorrow ni…
Jesus Christ and Christianity | World History | Khan Academy
We’re now going to talk about the beginnings of one of the most important religions in human history, and even today the largest religion on earth, and that of course is Christianity. The central figure in Christianity is Jesus Christ, and the term “Chris…
Creating a Zombie Soap Opera | StarTalk
What I did is I made it a super. I was like, what if people kiss while zombies are trying to eat them? And then people were like, I like this romance stuff. Relationships, really? Yeah, I mean, I don’t know. I’m interested in that kind of stuff. I mean, I…