Learning tools are teaching tools, right? Demonstrate certain scientific principles through physical objects. Let me teach you how to make your own optical fiber.
As the picture below shows, remove the bottom of a beverage bottle, connect a soft plastic tube to the cap, fill it with water, shine it with a spotlight pocket and the light can be transmitted to the bottom along the water in the tube You can turn!
? The next one uses a laser pointer as the light source, and the effect is more obvious.
? The principle is this: the refractive index of water is greater than that of air. When light passes through the water pipe, total reflection occurs at the interface between the water pipe wall and the air. the light can bend. This is the principle of optical fiber.
? This learning tool (teaching aid) is simple to make, illustbrings scientific principles to life and is suitable for primary school students.
? Don't forget to give me extra points!
What are the advantages of waterproof flashlights?
The first step is to prepare all the materials: a metal box with a plastic lid (like eight treasure porridge), 2 AA batteries, a 2.5 V light bulb and 15 cm of thin wire (you can use wire from a waste feeder), soft padding (bubble wrap, cardboard, rags, etc.).
The second step is to use a hammer to pry several times the center of the bottom of the tank in order to establish better contact between the bottom of the tank and the negative electrode of the battery
In the third step you can already see that the bottom of the. can is indented. Tin cans like this have a film inside. This affects the conductivity. You must use a hard object, such as a.hard object. a screwdriver, to severely scratch the box. Only by destroying this film can we conduct electricity efficiently.
The fourth step is to make a hole in the middle of the plastic cover. The goal is to attach the bulb to it. The holes should be made slowly from small to large, while comparing the size of it. the bulb with the bulb size. Do not make the holes too big, otherwise the bulb will not be stable. Before installing the bulb, remove the wire jackets from both ends of the thin wire. Wrap one end of the wire tightly around the bulb and pass one end through the side of the plastic cover. This section will become the flashlight switch. .
The fifth step is to connect the two batteries, paying attention to the positive and negative poles. Needless to say, you should use tape to secure them, and the connection should not be loose. Afterwards,wrap the exterior with soft stuffing, secure it with tape and place it in the pot. Finally, use padding to plug it in tightly so that the battery is in the center of the pot. Never let the battery sit in the jar. The jar is loose.
The sixth step is to close the cover so that the lower end of the bulb is in contact with the positive terminal of the battery. The exposed end of the wire is the switch when the wire touches the wall. from the tube, the bulb will light up.
Note: If there is paint on the outside of the can, it is not conductive, so the wire must contact the exposed part of the metal skin. You need to know where to contact.
The waterproof flashlight is a flashlight whose shell is made of ABS engineering plastic and is suitable for businesses, shops and other places. The bulb is a high brightness halogen bulb. The outer shellst in ABS technical plastic. Charging current 500mA, lifespan up to 100,000 hours, suitable forUsed for emergency in businesses, shops, homes, travel, driving, camping, etc. A flashlight that needs to be used underwater for a long time is not a simple waterproof flashlight, but a diving flashlight must meet the following conditions and precautions: a sufficiently long-lasting battery and a flashlight easy-to-use fixed pocket. auxiliary tools, such as straps, rope. Do not hit hard objects with a flashlight in water. Do not rotate the head and switch parts underwater. Check whether the connecting parts have been tightened before entering the water. Pay attention to the underwater depth indicated on your flashlight and do not exceed the rating 6. Remember to clean it with fresh water and dry it after use.