 Welcome to San Francisco Public Library's STEM Challenge series. My name is Vinnie and I am one of the children's librarians who will lead you through one of our STEM activity kits available at each SFPL location this summer. Our project for today is do-it-yourself kites. Now first, let me go over the science of what makes a kite fly. So kites fly using lift provided by the wind to push it up. Lift is created when air moving over an object is faster than the air moving under an object. Now this is because faster moving air creates less air pressure and slower moving air creates more air pressure. When the wind hits the kite at an angle it deflects the air downward creating a small pocket of slow moving air which increases the air pressure pushing the kite up. When the kite deflects enough air or catches enough of the wind then enough air pressure overcomes the gravity of the kite letting the kite fly. So let's begin. First you will want to get from your kit one sheet of paper and one length of string. So for our first design this is all you need from the kit. Put the rest of the materials aside. Now materials you need that are not included in the kit that you will still need for this first design are some tape or a stapler if you have that instead and something to make a hole with. So this could be a hole puncher or even just a sharpened pencil so as long as it has the tip. Now with your sheet of paper you want to fold it in half so that the short edges meet like this. Then taking one corner from the side opposite this crease you want to take the first layer here and bring it over to this folded edge. Now it's very important that you don't fold this yet so think of it like you're almost making a cone. So you want to hold that down and then repeat on the other side matching the corners to where you put it. Put the first one. So you're going to hold that together. Now the angle where you put this corner is up to you. So you can bring it up here. You can bring it down here. That's going to change how the kite flies so that's the place where you can experiment to see which position works the best. But once you've decided then either get your piece of tape or stapler and tape these corners so that they stay in place. Then you're going to get either your hole punch or a pencil and make a hole anywhere between the top of your kite and the place where you secured the corners. So I'm just going to use a hole punch here. Go right there. And once you've made the hole you're going to get your length of string. Your string will be longer. But you're going to get your string and put it through the hole. Tie a knot. So to make sure that the knot is secure on the kite, you may want to tie a second knot too. OK. And that is our first kite design. Now for our second kite design, you will also get from your kit one sheet of paper, another length of string, a ribbon, and one dial stick. So one of the wooden dial sticks. Some materials that are not included in this kit that you will also need for this project are once again some tape, something to make a hole with. Either the hole punch again or again you can also use a sharpened pencil to poke a hole through the paper. For this design, you will also need a ruler or anything with a straight edge on it. Because the next step after you fold the paper in half is to mark two dots. From the side where the fold is, you want to go about an inch. It doesn't have to be exact. So just about an inch from the folded side. And then on the bottom of the paper, you want to be about an inch from the open side. So you make these two marks and then you use your ruler to draw a line between them. Then you will fold along this line. So match up the marks. It's OK if they're not 100 percent perfect as long as you get this general shape. Then you're going to flip the paper over and then fold down this corner to match the one from the other side. So it's almost like folding a paper airplane. Now once you have this shape, you're going to unfold one of the sides. Then tape along this seam here so that it stays in this shape. So once we have this tape down, you're going to take the wooden dowel that you have and place it across the widest part of this of this shape here. And then you will also tape this down. OK, so once you've taped this down, then you want to flip your kite over and stand up this spine here. And then anywhere near the top, maybe about an inch away from the top of the kite, you want to either use a hole punch or use your pencil to make a hole right there for your string. And once you have that hole, you can get your length of string and then tie a knot around it securely so that it won't untie when the kite is flying. And like with the first design, you might want to tie a second knot just to make sure it's tight. Now, I didn't forget this ribbon. So if you've seen some pictures of kites before, this is starting to look more like that usual shape. And usually there is also a tail that flies from the bottom of the kite. You can tape your ribbon to the bottom and it is up to you how long you want your ribbon to be. So why is there a tail at the end of these kites? The tail of a kite provides air resistance or drag. And this actually slows down the kite, but it gives it stability so that when it flies, it doesn't just spin all over the place. So the longer the tail is, the more drag you produce. And the shorter the tail is, the less drag. So you can also experiment with the length of the tail to see how well it flies with your kite. But that is the finished second design. Before our third kite design, these are the items that you will need. From the kit, you will get one sheet of paper, two of the wooden dial sticks, another length of string, and another length of ribbon. The materials that you will need that are not included in the kit are a ruler or another anything that has a straight edge on it, a pencil, a pair of scissors, and some glue. You can also use tape with this project, but glue will make your kite stronger. All right. So to start, we are folding this piece of paper in half again so that the short edges are meeting like this. And this time we are going to cut this paper in half from this mold. Then on one sheet of the paper, you're going to put a very thin layer of glue all over the paper. So spread the glue all over the paper. Then you want to take the other half and place it on top so that you're creating one double layer of paper. And once it's on, you want to spread or make sure that there's no air bubbles inside. So just kind of smooth down the paper as much as possible. And when you're doing this at home, please leave the paper to dry so that the glue dries before you continue with the next step. But once the glue is dry, you want to get your ruler. So you're going to make four marks on this piece of paper. For the first two, you want to measure about halfway between the short edge. That's about two and three-fourths of an inch right there. And then make the same mark on the bottom of the paper. Two and three-fourths inch right there. So that's your first two marks. And then your second two marks are from the top of your paper. Make another mark about three inches down and then do the same on the other side. Once you have your four marks, you're going to draw a line between each of them, making a diamond shape like this. Now, once you have a diamond shape on your paper, you're going to cut that out. And that is going to be your kite base. And here is the base of your kite. All right. And now once we have our kite shape cut out, we are going to glue our dowels in a cross shape. So if you glue the dowels down, it will make the kite a little stronger. But for the sake of time in this tutorial, you can also use some tape, which I'm going to do instead. So start by taping down the dowel that goes across the wide part of our kite. If you have some that sticks out, just make sure that you tape it down. And then for the second dowel, you want to tape this or glue it so that it crosses over this first one. You may have to bend the kite so that it meets at least the ends of the dowel like this. And once you have the dowels in place, if you are using glue, please wait for the glue to dry. Before moving on to the next steps. But if you've taped it like I did, then you want to get your string. Slip it under this top dowel here and tie it right where it meets the other dowel, where it makes the cross. If you want to make sure that the knot is secure, tie another knot. And then as the final piece, please take another strip of your ribbon and you can glue or tape it to the bottom of your kite. And that is the finished third kite design. And as with all of the other designs, once you're done, feel free to decorate the back of it before you fly. So once you have all three kite designs, this is where you can experiment and try them out. Which design do you think will fly the best? For a further challenge, if there are some kites that don't fly as well, how do you think you can redesign these kites so that they will fly even better? So we already know about lift, trying to get the body of the kite to catch as much wind as possible to create more lift so that it can fly better. And we also learned about air resistance and drag from the tail. So do you think the kite will fly better with a longer tail or a shorter tail? So these are all questions that you can answer and experiment for yourself as you test out these kites and maybe even design your own. Just using what we've learned today to make the best flying kite that you can. Thank you so much for joining me today and I do hope you enjoy going out and flying your kites.