DENJIRO: Today, I’ll show you a mysterious phenomenon using this bottle. The bottle is filled with water. It’s about 80% full, and there’s some space at the top. I’m going to have a crew member strike the mouth of the bottle.
BOY: The bottle broke!
DENJIRO: The bottle broke, as if the bottom popped out. Let’s use a high-speed camera to see the secret behind what happened. When the mouth of the bottle is struck with great force, you can see that space is created at the bottom of the bottle. This is the key.
When the bottle is struck hard, the water stays in the same place, and only the bottom moves down. When this happens, a vacuum is created between the bottom of the bottle and water. When this happens, water strikes the bottom of the bottle with great force when it moves down. This force is what broke the bottle.
Great force created by water such as what we saw is called the water hammer phenomenon. Now, let me introduce to you an easy way to observe a water hammer. This is a test tube with colored water inside. Even if I shake it vigorously, a water hammer does not occur since there is no vacuum. Now, let me take the stopper off and heat up the water to make it boil. When the water is boiling, water vapor is produced, and oxygen is pushed out.
I will now place the stopper back on and cool the test tube. Now the water vapor turns back to water, and there is a vacuum between the water and stopper. I’m going to take out the test tube and shake it.
BOY: It’s making a sound!
DENJIRO: This is the sound of water striking the bottom of the test tube. That means the water hammer phenomenon is taking place.
NARRATOR: At hydroelectric power plants, when there is a sudden change in the amount of water flow or when the generator suddenly stops, a water hammer may cause damage to tunnels. Therefore, a large tank called a surge tank is installed. When water flow suddenly increases, water is drawn into the surge tank to prevent water hammers.
DENJIRO: I hope energy will bring you all happiness. Our magic word is "Happy Energy!"
Негізгі бет Ойын-сауық The Power of Water -Water Hammer / Mr. Denjiro's Happy Energy!
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