Material
Hot glue gun, 2 straws, 10 disposable cups, 3 pigments, scissors
Steps
1. Use scissors to cut a small hole in the middle of the three plastic cups.
2. Insert the short end of the straw into the small hole and make the mouth of the straw close to the bottom of the plastic cup.
3. Use a hot glue gun to fix the part where the small hole and the straw are connected, and pay attention to sealing.
4. Cut the straw short, a little longer than the bottom of the cup is enough.
5. Superimpose 10 disposable cups to form a trapezoid. Place the cup with a straw on the top of the first three vertical rows, and at the same time extend the lower outlet of the straw into the previous cup.
6. Put a few drops of pigments of different colors into the 3 cups with straws, and pour a small amount of water into the 3 cups, which must be lower than the hole.
7. Pour clear water into the cup at the top, make sure the liquid level is higher than the position of the small hole, and then observe the flow of water in each cup.
Principle
Experimental phenomenon: Pour water into the cup, and the liquid level in the cup continues to rise. When the liquid level does not exceed the position of the small hole, the liquid level in the straw in the cup is level with the liquid surface in the cup; when the liquid level is higher than the position of the small hole, water starts to flow out of the straw and into the front cup. When the liquid level in the cup is lower than the position of the small hole again, the water in the straw will still flow out until the bottom of the straw in the cup is flush with the liquid surface. Finally, the water in the three cups is collected in the bottom cup.
The siphon phenomenon is the phenomenon of using the force of the difference in liquid level. After the liquid is filled into an inverted U-shaped tubular structure, the high end of the opening is placed in a container filled with liquid, and the liquid in the container will continue to flow through the siphon tube. The lower position flows out.
