Kneel down and beg for the physics gizmos of the second year of junior high school, to be small.

1.Simple magnifier (convex lens principle).

Dig a hole in the paper, then attach a transparent film (plastic bag or plastic wrap) to the hole, and put a drop of water on the film. And that's it. Place a magnifying glass on the words in the book to see the effect.

2.Tumbler (gravity principle).

Split the table tennis ball into 2 halves, use half of them, glue plasticine to the bottom of it (not too much), close the upper opening (arbitrary shape, not too heavy), and you're done.

3.Periscope (principle of reflection of light).

It's easy to make, so let's not talk about it.

Does the teacher want you to do it? Can't it go beyond the scope of the second year of junior high school? There are not many small experiments in the second year of junior high school, and if you do simple ones, such as soil **, such teachers probably don't like it.

I suggest you find a way to make a colorful fountain. The color used the dispersion problem of the light. If you want to make colored light, you can buy a light bulb like that.

Just power it up. Ask your parents, they should know. Hopefully I can guide you one or two.

Make a kaleidoscope, glue three flat mirrors together to form a triangular pyramid, and put a flower in it. It's not an invention, it's just a clone.

It's a periscope!! You can try it!!

Let's make a water rocket, although I learned it in elementary school, but there is junior high school knowledge in it, believe me, as long as you do it well, the teacher will definitely like it

This is on the **, there is, a small production of science and technology material package. I bought a lot, what vacuum cleaners, cars that can walk, sound and light can be used. You search.

You can make slippers, you first find a pair of slippers, then take a sponge or handkerchief, glue the wooden board or cardboard to the shoe board, cut it into strips, and finally glue it to the wooden board or cardboard with adhesive tape, and you're done! So when you want to watch TV, and you want to mop the floor, you put it on, put it on with water, wring it out, and watch it while taking it off, which is very convenient!

Make a generator! The picture above is a sketch of the assembly plan I drawn.

Light-emitting diodes.

Wire engine (motor).

Adhesive tape (fixed motor).

Small planks or tables (carriers of motors).

Cotton thread note: the material is easy to obtain, the principle is simple! Assemble it like I drew it, wrap the cotton thread a few more times, and pull it faster!

The specific method of modifying a small electric fan by yourself: you are a post-90s generation, have you ever played a four-wheel drive car, remove the motor, make a simple battery box according to the original circuit connection, connect the linkage rod of the motor, paste a few pieces of paper on it, practice the circuit, and a simple small production will become.

If it is a small invention and does not want a physical object, I recommend setting up a light-sensitive and sound-sensitive electronic control switch circuit, which is relatively easy.

Summary. Looking for a science and technology gadget suitable for junior high school students, urgent! Don't be the kind of ...... you're ashamed to take it outAdd another wire.

You can drive him to turn.

You can also try your hand at water rockets.

Homemade flashlight.

The specific method of making it is to remove one end of the lid of a waste can (such as a Lulu beverage can) and knock the other end with a round hammer. Roll up two No. 1 batteries with thick corrugated cardboard and put them into the tank with the positive electrode facing up and the negative electrode facing down.

Find a suitable plastic lid (such as a magic big roll lid that can be fastened to Lulu cans) and dig a small circular hole in the lid** in such a size that the bulb is plugged in tightly. Insert the base of the bulb into the small hole. Take a piece of wire hunt and peel off the wire skin at both ends, wrap one end around the lamp base, and pierce a small hole through the side of the plastic cover with the other end.

Place the plastic lid over the can. Check that the bulb and battery are in close contact. At this point, the disposable flashlight is ready.

When using, use your thumb to press the wire threaded from the side wall on the weld that is not painted from the can, the flashlight will glow, and the thumb will jump off the wire, and the flashlight will go out, which is very convenient to use.

Homemade bai periscopes.

Buy two small mirrors. du

Use pieces of cardboard to make two right-angled curved round cylinders, slightly larger in diameter than a small mirror. Open a 45-degree oblique opening at each of the two right-angled parts of the special paper tube, insert two small mirrors into the oblique mouth relative to each other (as shown in the figure), glue it with a paper strip, and put the two right-angle cylinders together, that is, a simple periscope.

Periscopes are used for a wide range of purposes, including in infantry trenches to observe the battle ahead, as well as in the cockpit of tanks and for gun commanders. By making a simple periscope, students can understand the reflection phenomenon of light and the principle of optical path design.

Homemade sprayers.

Production method] take a glass bottle, insert two slender glass tubes A and B on the stopper, the lower end of tube A should be extended to close to the bottom of the bottle, its upper end is exposed outside the bottle, at right angles, and a section of rubber tube with spring clamp is sleeved, and the other end of the rubber tube is connected to a glass tube with a pointed mouth at one end of the bottle with a rubber tube and the injection head of the syringe.

How to use] first fill the bottle with water close to the bottle mouth, so that only a small amount of air is left in the bottle, and assemble it according to Figure 5 15 12. Water is then injected into the bottle with a syringe and the plunger is kept in place, and then the spring clip is released, and the water is sprayed out of the tip of the glass tube C in a mist form.