20 Experiments with Magnets and Magnetism STEM Jojo Science show Ep 45

Have you ever wondered how magnets work? Well stay tuned because you're going to find out. On this episode of Jojo Science Show. This thing is crazy. Let's try it out now and see if it's a magnet. Awesome. Awesome. Wow. We did it. Hey look. We built a car. Look how we're making the magnet float. You see those spikes? You can't see me. But now you can see the light. Wow. It's making spikes by lining up with the magnetic field. Hello. Welcome to Jojo Science Show. We're going to do 20 experiments with magnetism. Moving electrons make magnets and moving magnets make electrons move. Kids make sure an adult is supervising you if you're doing any of these experiments because magnets, batteries, and copper can get hot when they interact with each other. For this experiment we're going to make a magnet. You'll need two safety pins any size. You'll need an N52 neodymium magnet. To make this work I'm going to rub my magnet across the safety pin about 50 times so that it becomes magnetic. Only rub it in one direction. Let's try it out now and see if it's a magnet. Awesome. What makes a magnet a magnet? Let's zoom in all the way to find out. Magnets have domains which are a collection of atoms. All these domains need to have their magnetic fields pointing in the same direction. Let's zoom in further. Now we can see the collection of atoms all lined up with their magnetic fields all pointing in the same direction. Let's zoom in even further because we still don't know where the magnetic field is coming from. Oh look it's Eli the Electron. He's going to explain to us where the magnetic field is coming from. Hi kids it's me Eli the Electron and I have a negative charge. Moving charges make magnetic fields. When I spin I'm a spinning charge that makes a magnetic field. I like spinning. When I'm unpaired and by myself there's nothing to cancel my magnetic field. But if there were two of us we would spin around in opposite directions and cancel out each other's magnetic fields. To be a magnet you need to have three things. You need to have unpaired electrons which make up the atoms. You also need atoms that line up with each other and you'll need domains which are collections of atoms that also line up with each other. If the material doesn't have all three of the properties it will not be a magnet. By rubbing the safety pin 50 times we lined up the domains and made the safety pin magnetic because the iron already has atoms lined up and unpaired electrons. I'm going to make an electromagnet. All you'll need for this experiment is some insulated copper wire, steel rod, and a battery. Make sure an adult is supervising you. See this rod is not a magnet. The first step is to wrap this the insulated copper wire around the steel rod. Now I have it wrapped around the rod. Now connect the battery to the ends of the copper coil. The ends are not insulated so I can connect them to the battery. Now the steel rod is an electromagnet. Isn't that cool that it can pick up another bolt? And this and this. This is a fun ride Mr. Magnet. Look how he picked up this toy car. Did you know they use big electromagnets to pick up real cars? Look how many things I picked up. Here's my friend Eli the electron and he's going to show you how electromagnets work. Eli has a negative charge. When charged particles move they create a magnetic field. The battery has a force that pushes Eli around the track. This force is called voltage or EMF. Electromotive force or as I like to say electron moving force. When Eli moves around the copper coil he magnetizes the steel rod. Now that the steel rod is magnetized it attracts the paper clips. Did you know that the earth has liquid inside of it? This liquid has charged particles in it. When these charged particles move it gives the earth a magnetic field. Do you see the magnetic field around the earth? Did you know our Milky Way galaxy has a magnetic field because of all the moving charges in space? See how many things I picked up? For this experiment we're going to make an electric motor. First you take a c-size battery. You'll need a big button magnet and then you attach it to the side of your battery like this. Take two safety pins and put them on each side of your battery with some electrical tape. If you put the magnet on first then it helps the safety pins to stay on. Next you need to take a copper wire and make a loop. If you want you can use something round like a glue stick to wrap it and don't start right at the end. Take both of your ends and wrap it around just like this. Do that a few times until it's secure. You can place your magnet back on the side of the battery. Take some sandpaper like this. Sand off one side of each end like this to remove the insulation. Make sure you don't do it on the opposite end once you already have sanded one end otherwise it won't work. Put your copper coil ends through the safety pins. Let's see if it works. It works. I don't even have to hold it. For this experiment you'll need a AA battery and a stack of button magnets or a big magnet and some bare copper wire. Bend it until you have sort of a heart shape like this and then this and then this or a square with that with a notch in the top like this. This is what we ended up with. This part will touch the positive pole and this part will touch the magnets. Be really careful because this copper wire can get really hot. So we just put it on and weee. Look how fast it's going. That's awesome. All electric motors work because an electric current and a magnetic field causes a force called the Lorentz force which spins the motor which relates force magnetism and electricity. For this next experiment we're going to make a super fast homopolar motor. You'll need aluminum foil, a battery, three button magnets on top and on the other side a big magnet. First take your aluminum foil and roll it into a tube. Close up one end like this. It's like a wind-up toy. This thing is crazy. This is another homopolar motor. This is better than a fidget spinner. I don't even have to spin it with my finger and it spins much faster. For this next experiment we're going to make a battery roller. This is a type of motor. You'll two neodymium magnets like this with holes in them and you'll need one battery about this size and a long sheet of aluminum foil. Put one of them, wow that's a strong, put one magnet on one side of the battery and the next one on the other. If you turn it then it'll go in the other direction and I just turn it like this. It also works with the AAA battery and three button magnets on each side. It works really well. It goes really fast. This is a type of homopolar motor. Deck the halls with rolls of foil. Now we're going to see if we can get it to roll all the way down the hall. Wow look at it go. We really did it. After a few tries we actually did it. I'm Mr. Battery and I'm coming back to you. For this next experiment you'll need a cardboard tube, a piece of aluminum foil, some scissors, a AAA battery with three small button magnets on each end and you'll need some tape. Roll a piece of aluminum foil until it looks like a cylinder and then you tape it closed. When you're finished you should have this. Now slip your aluminum foil into your cardboard tube and now put your AAA battery with three button magnets on each end inside. Hey look we built a car. For this next experiment we're going to make a magnet powered train. You will need a AAA battery and three small button magnets on each side. You'll need a half inch PVC pipe, a roll of uninsulated copper wire and a barbecue skewer. You may need some help with this. Wrap it around your pole until you get something like this. Each line should be about one skewer apart. Now we have a copper spring. This is fun. It's like a slinky. Well at least we made a buzzer. First we tried a AA battery but that only made a buzzer so let's try a AAA. Ah it goes super fast now. See the plus side is here so I put it in and on the plus side it goes. The electricity from the battery flows into the copper coil making it an electromagnet. One side of the train's magnet are repelled pushing it away while the other side is attracted in the same direction. This pushes the train forward. For this experiment we're going to see how electromagnetism is used in speakers. This will teach us how speakers work. Speakers have magnets and copper coils so that they can turn electrical signals into sounds. Speakers have a permanent magnet and an electromagnet which is used to pull a cone back and forth. This cone creates air vibrations which we hear as sound. For this experiment you'll need an electric motor. You will need a phone with a headphone jack. You'll need a pair of old headphones and a paper cup. A DC motor has copper coils and a magnet in it and when we send electrical signals it can cause vibrations in the DC motor. We can try to transfer these vibrations to a cup to see if we can hear the sound. First cut the headphone wires. Peel back the insulation so you can see the exposed wires. Now connect the two poles of this motor to the wires. Poke a hole in the bottom of your cup with the shaft of your motor. I'm going to hold it up to the mic so you can hear it. Now this is not practical and you will look silly walking down the street with a cup over your ear but this is a great and easy way to learn how speakers work. For this experiment you'll need two grapes, two small wooden sticks, you'll need some fishing line, and a magnet. You'll need something to hang your fruit from. We have a PVC pipe stand. First we're going to set up our fruit by putting it on the wooden stick. A grape baton. Next take two long pieces of fishing line and tie with one end tightly around your sticks. You can always cut it shorter if it's too long. Next you have to tie up your fruit. I'm hanging mine on my PVC frame. Perfect. Next you'll have to try and balance your grapes so that they hang even. See how these grapes are standing still? Let's see what happens if I don't touch it with a magnet but hold up a magnet to it. Look it's moving and I'm not even touching it. It's going faster. This is called diamagnetism and when a magnetic field is applied the fruit is repelled and is moved in the opposite direction. Fruit is diamagnetic which means it generally doesn't have any unpaired electrons. Diamagnetic materials have a weak repulsion to strong magnetic fields. For this next experiment we're going to make a solenoid. A solenoid is like a switch that is controlled by an electromagnet. This is a solenoid. When we apply a voltage to it then this will move. Solenoids are used all around us in valves that open pipes and can be used to unlock doors and for many other uses. We're going to make a solenoid from an electromagnet so you can see how it works. You'll need some batteries. You'll need a test tube, some insulated copper wire. You'll need a nail and a small magnet. Wrap the copper wire around the test tube. Now that we have it all wrapped take a piece of tape and tape it in place. Make sure the end of your copper wire is not insulated. If it is use some sandpaper to rub it off. Our solenoid is completely built. Let's try it out. Hey look I have the power to make magnets fly. Do you see how the electromagnet attracts the other magnet and causes it to move? The magnetic field from the electromagnet is attracting the permanent magnet. This is how solenoid works. It can also repel. Look how we're making the magnet float. It can also attract pieces of metal like this nail. Wow it works. Today we are going to make a flashlight that uses electromagnetic induction. All you need for this experiment is a magnet, insulated copper wire, an LED, a tube, two alligator clips, and tape. The tape has a duck on it but I don't think it's duct tape. LED stands for light emitting diode. It lights up when electricity is flowing through it. I am going to teach you some fancy words. Electromagnetic induction. If a magnet moves through a copper coil it makes electrons move and makes electricity. This is called electromagnetic induction. Here's my friend Eli the electron and he's going to show you how electromagnetic induction works. Eli is on the copper coil. When he feels the magnet getting close he starts to move around the track. His energy is electricity which lights the LED. A lot of the electricity that you use today is made by electromagnetic induction. The first step is to wrap the copper wire around the tube. You have to wrap a lot of it. Now that it's wrapped we have a copper coil. The next step is to put the magnet into the tube. Then tighten the cap on the tube. See how the ends are not insulated? Now connect the end of your copper wire to the alligator clips. Now connect the alligator clips to the LED. Now our flashlight will work. Every time I shake this tube the magnet moves through the copper coil. It makes electricity. Every time I shake this tube it lights up the LED. You have to shake it really have to shake it really fast. Move in the light so you can see it. If we attach two LEDs then we can have two colored lights. For this experiment you'll need two neodymium magnets. You'll need a copper pipe and a PVC pipe of the same length. This is a very strong magnet and this copper is not ferromagnetic. See how it doesn't stick? You can see it also doesn't lift it up. I'm going to hold these two pipes and drop the magnets at the exact same time. We'll see which one lands first. The one in the copper pipe or the one in the PVC pipe. Let's get started. It's the magnet battle. Three, two, one, go! See how the magnet moves slowly down the copper pipe? This is because of eddy current. Did somebody say yeti? Not yeti, eddy. Go eat some spaghetti. An eddy current is a current that moves in a circular pattern. Do you see how the falling magnet causes Eli the electron to move in a circular pattern? The moving electrons create a magnetic field that slows down the falling magnet. Eli doesn't really want to move, so that's why he resists the falling magnet. This also works with copper wire as long as it's not insulated. Look, it falls so slowly I can drop it and catch it with the same hand. Did you know they use eddy currents to slow down roller coasters and trains? Ah, eddy currents stop this train. Do you want to see my jumping magnet trick? And it flies off in the sky. Aluminum isn't ferromagnetic. See how the magnet doesn't pick it up? Magnets are not attracted to the aluminum like they are to iron or steel, but if you drop a magnet through a roll of aluminum foil, it will hover down slowly just like it did through the copper pipe. That took a while to get down. This roll of foil weighs 2.6 pounds and it's really heavy, and I'm going to move it without even touching it. This way, this way, this way. Do it about this fast and you can move it. You can even feel it. Do you see it moving? If you drag it all the way, you can feel it resisting the motion. It's really cool. We've made a magnetic pendulum by tying this string to two magnets. Let's see what happens when we swing it over the roll of aluminum foil. Yeah, it is affecting it. The eddy current induces a wobble on the pendulum. See how the eddy current resists the magnet and causes the pendulum to stop swinging quickly? With an even stronger magnet, it stops the movement very quickly. You can see this clearly from the side. Today, we are going to make a ferromagnetic liquid. A ferrofluid responds to a magnetic field. For this experiment, you'll need some oil, some liquid soap, some black pigment called magnetite. It is called magnetite because it is attracted to a magnetic field. It's made of iron oxide. Can you see how the magnetite moves when I move the magnet? If we suspend magnetite in a liquid, then it becomes a ferrofluid. The first step is to mix a little bit of the magnetite with the soap. Now, add a few drops of soap. Mix the magnetite with the soap as best as you can. Next, add the oil to the magnetite very slowly and mix. Mix it until it becomes one color. Add more oil, mix until you work out all the lumps, and then you have a smooth black liquid. You see those spikes? That's the magnetite. It's lining up with the magnetic field. This is cool. I like it. For this experiment, we're going to make a compass. A compass aligns with the Earth's magnetic field and points north. A compass will help you find your way if you're lost, and we're going to build one. First, you take a needle and rub a magnet on it 50 times. You can put a cork on the sharp end of the needle so you don't get hurt. Okay, that was 50. You'll need a shallow bowl of water to float your needle in. We use a piece of foil to help the needle float. The end you magnetize will point towards north. Even if I twist the bowl, the magnet will still point north, even if I twist it really fast. Do you know what a dynamo is? A dynamo is a machine that can turn movement into electricity. Electric motors have magnets and copper coils. When magnets move near to a copper coil, it causes the electrons in the copper to move and makes electricity. This is called magnetic induction. For this experiment, you'll need an electric motor, two alligator clips, and an LED. First, connect your alligator clip to your electric motor right here on one of these things, and you connect the other side to one of the sides of the LED, and you do that same thing with the other one. Okay, see? It's as easy as that. Wow, it's lighting up the LED. See how when you turn it, it blinks? This electric motor is turning the motion of my hand into electricity. If this electric motor had a handle, we could keep the LED lighting up. So that's why we bought this dynamo torch kit. If you buy a dynamo kit like this one, you can build a dynamo with a handle. That makes it easy to spin and gears to turn the motor really fast. Wow, it works! The gears work because when I spin the handle one revolution, it spins the motor many more revolutions. You can't see me, but now you can see the light. We're going to do some mining. I'm going to show you how to extract magnetite from beach sand, and the magnetite inside of the beach sand is completely natural. This is a very easy experiment that you can try when you're going to the beach. Magnetite is a mineral or a type of rock that's found in the earth. Magnetite contains iron, and it's also a type of iron ore. Magnetite is known as magnetite because it is attracted to a magnet. All you need is a strong magnet and some beach sand. You can also try this experiment with soil if you don't live close to the beach. Now we're going to take a little field trip to the beach. Let's rub our magnet in the sand. See the black particles on my magnet? That's the magnetite. After just a few minutes at the beach, I had all this magnetite. Let's make it stand on a plate. You have to hold the magnet a little bit away from the plate if you want it to spike. Wow! It's making spikes by lining up with the magnetic field. Thanks for watching JoJo's Science Show. If you like this video, hit the thumbs up button down below, and subscribe to my channel so you can see all my fun videos. 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