 Welcome back to Kids Fun Science! My name is Ken. Today's experiment is the Exploding Watermelon on National Watermelon Day. As always, adult supervision is required. What you need for this experiment is three to four hundred rubber bands, a box to hold it up, and a watermelon. Here are the rubber bands I'm using, size 64, three and a half inch by a quarter inch, or 88 millimeters by 6.4 millimeters, and you can get them at your local office store. Alright, welcome to Kids Fun Science. Today we're doing a watermelon experiment with rubber bands, and using the potential energy of pulling in the watermelon into the sides, and then it's going to explode. So what you do need is safety goggles. If you're gonna do this at home, so we got those. We got a box to hold the watermelon up, and then we're gonna be putting rubber bands on it as we go. So we will come back. As we continue to put rubber bands on, we start to squeeze the melon. That pressure from the outside is forcing the watermelon to put the place somewhere else. So it's gonna start bulging, looking like maybe a number eight in the middle. Rubber bands are a great example of potential energy. Potential energy is energy that is stored up, not being used, just waiting to be unleashed. So think about when you stretch your rubber band, you let it go and it snaps back. It's using up that potential energy. When potential energy is used up, it becomes kinetic energy, energy in motion. So right now, all those rubber bands around the watermelon are stretched out full of potential energy and ready to snap back. And we're gonna find out what's gonna happen with all that potential energy. So you can see it's starting to pull in right here, and we're gonna continue to put it on. We're doing about three or four rubber bands at a time. Yeah, it's definitely starting to pull in. Make sure you're wearing safety goggles on here. You never want to lean over the top of this because it's going to explode out. So you always want your face back away from it. So once again, we're putting on three or four rubber bands at a time to speed up the process. We believe when we do this, the number of times that we have done this, when you start doing one at a time, eight's gonna take you over 30 minutes to do. By doing three or four at a time, you could cut the time down drastically to 15, 20 minutes. And you'll be able to know when the thing's going to explode. You can start seeing the sides go in, but definitely every time ours explode, and I don't want to say it's gonna happen every time. But there's a little bit of liquid starts to squeeze out. And once again, do not put your face above the top or close to the watermelon because the potential energy is going to squeeze in and it's going to explode the watermelon outwards. So we want to stay back arms length as best you can on this. And when we start seeing liquid, we go down to one rubber band at a time after that because we want to be able to see it take off. So that's definitely the best time to set everything on slow mo or everything like that. When you start seeing liquid, you're very, very close for this thing to explode. So just continue to keep doing this. Grabbing three or four at a time, easy. Just one person grabs them and the other person just pulls it back and slide it over. Another tip is to try to keep it like a belt right in the middle. The more you spread it out, the higher it goes, the longer it's going to take to get that watermelon to explode. So you can see here, we're concentrating on keeping it all in the middle. And we want to get it exactly over there. See, I was trying to do one at a time and by yourself and it just doesn't work by yourself. So you definitely need a two person thing there. So we see the liquid coming out there and it's starting to move. I'm trying to keep it centered up straight. So it shoots off. So it doesn't shoot, you know, off to the angle or anything like that. So continue to keep doing this and we'll start to see the watermelon pull in more and more and you're going to get that number eight look where you get those two curves like an eight coming in there and we're starting to see that right now. And it's starting to pull in and that potential energy is just getting too much on the melon and it's going to get to a point where it just can't take it anymore. And so we're probably well over I'd say over 220 225 rubber bands. I'll give you a final count at the end. Usually it takes us I've had up to 320. I've been down to 290. So it's the average I say right in there just really depends on how big a watermelon you get and the longer you leave it on your counter, the more it's going to explode because it builds up some energy itself when it's on the counter. You ever cut a knife into it and it just kind of explodes out. So a nice fresh one works perfect. Pouring out water right here. It's coming out. It's got the juice is coming out right there. It's starting to squeeze. It's going. Alright, so here we go. We're going to start doing a slow motion because it's going to go now. So it's going to explode any minute. You're gonna see as we pull down this last rubber band. We're doing a single rubber band this time and when you pull it when we're pulling it down on my son's side on the left hand side you're gonna see some liquid pour out because this this is really the potential energy is just pushing in on the poor watermelon right now it's starting to look like a number eight as it comes down right here to the left you'll see some liquid it's gonna pull down right there. There goes the liquid over his wrist and it's gonna explode before we even get this rubber band on so start to be ready and it is boom. It was a pretty pretty explosion. That's why definitely why you're wearing your safety goggles right here. The top part is still up in the air. You're gonna see it come down in about a second or two. It almost hit the top of the patio. It's still up in the air and it's coming down because we are in slow motion and here it starts to come down and it's gonna take a wallop onto the table of the whole second part of the watermelon and then I don't know if you can see which I'll share in a second but to the right side of the table there's a ball and that's the ball of rubber bands because of all the potential energy kicked off and just squeezed it right into a single ball which I'll show you in just a second. I actually had another camera going that really catches the top part of the watermelon going up and I'm gonna show you that right here so this is my camera on on the base of the table and it goes backwards with the explosion once again you're gonna see the liquid come out by my son's left arm as he's bringing this rubber band down here because it's getting ready to go. There goes the liquid and it's going to explode before we even get that rubber band on again and it starts to go. It knocks the camera over and we're able to see the top part of the watermelon go up which is pretty incredible here knocking those rubber bands out. Here it goes to the top. It looks like we planned this but we definitely didn't plan it. The camera pushed backwards see it go all the way to the top and come crashing down. Once again safety goggles as you can see plus a humongous mess everywhere. It's absolutely just crazy. It's just crazy fun. I wish I had another watermelon. Definitely something you guys have to do before the summer is over. And that's a... I knocked my phone over. And that's and that's happy water National Watermelon Day and that's how you do it and look look at right here that's all the rubber bands right here that's crazy that all this wrapped up right into a ball. This is why you wear safety goggles. I hope you enjoyed this video. Remember to click thumbs up and to subscribe. Thanks for watching.