Using discarded mineral water bottles to make a motor boat with water level difference, you only need to prepare 3 mineral water bottles (of course, they can also be bottles plastic for other drinks) and follow the following method to make it. . Super simple scientific and technological production. Kids, please collect some discarded plastic bottles and let's turn trash into treasure~
Make a small hole in the bottom of one of the plastic bottles and thread a piece of pen through ball. pen tube through it. Tie the other two mineral water bottles to both sides of the perforated bottle with rubber bands so that the middle bottle is exactly in the center of the other two bottles (try a few more times and make sure you find the balance point, otherwise the middle the bottle will be filled with water. Fill the bottle with the middle.u with water and the boat will move forward under the power generated by the difference in water level!
Although the photo seems simple, it is not difficult to make. The biggest difficulty is that the center of gravity of the vertical bottle filled with water is too high, making it difficult to maintain the balance of the boat and causing it to tip over easily. Therefore, I suggest that the following two bottles be used as a shell. It is better to use the larger one, and the connection method using rubber bands is not very reliable. You can use handy chopsticks as supports and then use rubber. strips to bind them. Finally, adjust several times so that the vertical bottle is in the center of the hull's buoyancy.
Finally, it is not necessary to cap the vertical bottle once it is filled with water. If you tighten the bottle cap, water will not spurt out of the pgoes under the action of atmospheric pressure, and your boat going backwards will have no forward momentum!
Principle of the underwater experiment with a bottle of mineral water
Physics is everywhere in life. Chu Ming made several interesting experiments using mineral water bottles: (1) Squeezing an empty mineral water bottle with both hands can deform the bottle. If the applied force increases, the degree of deformation of the bottle increases, which shows the effect of force. is slow. Slowly deepen inward, indicating the existence of: (2) Inject a small amount of hot water into the empty mineral water bottle, shake it, pour it out, and immediately close the bottle cap bottle. is found. (3) As shown in figure a, place an empty mineral water bottle on a horizontal table and blow air to the side forcefully, and it will roll. However, if you blow air withc the same force towards the bottom, it will not roll. slide easily. This shows that. (4) As shown in figure b, drill the upper and lower holes at different heights on the side wall of the empty mineral water bottle, fill it with water, and you can observe the water flowing out of the two holes, among which the lower hole flows. The water spurts out faster, showing: This has become a thought question asked by the teacher. What is your choice? Question: As shown in figure c, there is a small hole at the bottom of the open container. After filling the water, open the valve and the water will continue to flow from the small hole. The figure below can roughly reflect the relationship between the pressure P of the water at the bottom of the container and the time t at which the water flows. The picture is
Answer: the size of the force
Atmospheric pressure
Rolling friction is less than sliding friction
Pressureof liquid is related to depth
B
Why can a refrigerator produce water vapor as long as it has electricity and no pipes water ? a bottle When you put in and take out the mineral water, there are not many water droplets on the surface of the bottle.
The principle of the underwater experiment with a bottle of mineral water is:
Under water, the pressure in below an empty bottle is greater than the pressure above it. So the bottle becomes more and more stressed as it goes down. This is different from water, where the pressure at the top of the bottle is equal to the pressure at the bottom. When the underwater pressure reaches a certain level, the mineral water bottle begins to be compressed by force, causing the air from the bottle mouth to enter the bottle, compressing the air that is outside. gaseous state.
Underwater, the water pressure increases, and theAir pressure inside the bottle as well as external pressure continue to increase, forming a carrier object heavier than water. This causes the bottle to gradually sink to the bottom. After deflation, the air escapes again, rebalancing the pressure between the water and the bottle, so that the bottle can once again float on the surface under the action of buoyancy.
To put it simply, the principle of the mineral water bottle submarine is to use the principles of buoyancy and pressure of physics to compress air to form a heavier object, allowing causing the bottle to sink to the bottom of the water. After deflation, the air diffuses and the corresponding gas volume becomes larger. At this time, the total volume of the bottle becomes larger and the buoyant force is greater than the weight of the bottle, so the bottle can float.
Production method:
1. Manufactureder the hull. Use a utility knife to cut a rectangular piece of rigid foam board, about twice as long as the mineral water bottle and about 1 to 2 cm wide. Draw a center line on the long side and fold it in half. Then mark 2cm scales on all sides along the folded line and draw a line from the two scales near the long side to both sides, intersecting the short side respectively.
Use a knife to cut inward along these two lines to form a triangle with pointed ends at the head and tail.
2. Make two small holes in the center of the hull, insert lead blocks and secure them. In this way, the descent speed of the mineral water bottle submarine can be slowed down and the bow of the ship can be tilted more easily.
3. Stick 1-2 layers of aluminum foil to the back of the submarine hull to make the surface mores soft to attach various toys and stickers.
4. Cut the mineral water bottle in half down the middle, leaving the neck and bottom of the bottle. Turn the bottom of the bottle over, press it flat and place it in the center of the boat. Use a wire hanger to secure the raised bottom of the bottle to the shell.
5. Put a piece of clear tape on the bottle neck and attach the bottle neck to the center of the arch. Thread a wire hanger through the mouth of the bottle to release the air filled in the bottle and allow the submarine to sink.
6. Hang a weight (such as a piece of lead) from the bottom of the mineral water bottle and the stern of the boat to keep the submarine stable and sinking.
Once the creation is complete, fill the mineral water bottle with water (not too full or the submarine will float), then press the bottle to let the gas out. WhenWhen the gas flows, the underwater mineral water bottle will quickly sink to the bottom of the water, release the water on the suspension line and the submarine will swim like a small fish!
The mineral water you mentioned was put in the refrigerator and there were a lot of water droplets on the surface of the bottle when it was removed. This was not produced by the refrigerator. Water vapor is a very natural physical phenomenon. When the bottle of mineral water is placed in the refrigerator for a period of time, the temperature of the mineral water drops very low, well below room temperature. At this time, there are no water beads outside the mineral water bottle. the fridge. When you take out the bottle, a frosty mist will immediately form on the outer surface of the bottle, and after a while, water droplets will form on the outside of the bottle. This principle is thatThe air contains water vapor. When it encounters a bottle at low temperature, it condenses into mist and sticks to the outer wall of the bottle. As more and more water vapor condenses, water droplets form. It is the same as dew in nature in summer and autumn. I hope to adopt him