The Properties of Rubber / Mr. Denjiro's Happy Energy! скачать в хорошем качестве

The Properties of Rubber / Mr. Denjiro's Happy Energy!

DENJIRO: This is another episode of "The Summer Vacation Science Project Special." What do you think this is? BOY: It's a ball. DENJIRO: This is actually a rubber ball made of rubber bands. As you can see, it bounces well. I'll show you how to make a rubber ball. Grab a bunch of rubber bands and make the core of the ball by wrapping rubber bands around them. Gradually form the core into a sphere. You can continue to use thin rubber bands, but as the ball gets rounder, thin rubber bands will tend to come off easily. So, once it starts to get round, switching to using thicker rubber bands will make things easier. Wrapping the thick rubber bands tightly will make the ball bounce well. If you continue to wrap the ball with rubber bands, it will become this big. Try to make a rubber ball that bounces well, and enjoy playing with it. Rubber is able to stretch. Using this property, we can make a simple scale. We have a rubber band suspended in a clear cylinder, and weights can be hung on the rubber band. But this is not enough to call it a scale. Here, we have a plastic bag with 20 ml of water inside, which equals 20 grams. Hang the bag on the rubber band and mark the spot where the rubber reaches. This is 20 grams here. I'll add another bag. That's 40 grams. Continue to add weight and add more markings. Here, I've made a rubber band scale that can weigh up to 200 grams. When you look at the markings, you can see that they are not spaced evenly. Unlike a spring scale, a rubber band scale does not get evenly spaced lines. This is another interesting property of rubber. Let's weigh this banana. BOY: That's about 150 grams! DENJIRO: Using a longer cylinder or a thicker rubber band will allow you to weigh heavier things. Make your original rubber band scale to weigh various objects. I hope energy will bring you all happiness. Our magic word is "Happy Energy!"