In the second year of junior high school, the plan is a little more complicated, but the materials a

Compared with the "small motor" on page 62 of the new physics curriculum standard for junior high school, the simple DC motor "magic top" assembly experimental kit (hereinafter referred to as the "motor kit") has the following advantages:

1. The shaft of the "motor sleeve" is much thicker than the enameled wire of the "small motor", and the shaft will not be bent when the paint is scraped with a knife, and the shaft is not easy to bend when the motor rotates.

2. The enameled wire of the "motor sleeve" coil is much thinner than the wire of the "small motor", and it is more convenient to wind the coil.

3. The "motor sleeve" is to wind the coil on the given plastic skeleton (it can be wound in the same direction), which is much more convenient and easier to succeed than the student using enameled wire to directly wind the coil without the skeleton.

4. The magnet of the "motor casing" is a 1000 gauss square magnet (two pieces), which is easier to obtain a single pole than a hoof-shaped magnet, and when demonstrating the experiment of changing the direction of rotation of the motor, you only need to turn the square magnet over and place it. Because of the strong magnetism, it is also easier to make an electric motor (the coil only needs to be wound a few times to succeed).

5. The motor bracket is changed to two parallel tracks, which can also make the rotor roll around on the track, which increases the interest of the experiment (also known as the magic top), (see application 2) and also increases the contestability of the experiment

2. Popularization: Provide equipment according to the requirements of page 62 of the new curriculum standard "small motors", so that students can wind coils and make motors by themselves, which is easy to succeed. The average student can complete it in 30 minutes, and the success rate is more than 90%.

Change the direction of rotation of the motor's rotor (just turn the magnet over).

3. Improvement: (Make-and-Lose Competition).

A: On the basis of making the motor, let the rotor roll back and forth on the rail guide (make a magic spinning top). Rolling is only as good as a student's hands-on ability and innovative spirit.

You can roll the rotor 10 times 、......100 times? Let's show off your skills!

For example, if a small light bulb is connected in series between two tracks, it can be measured whether the track is connected to the battery (flashlight circuit).

Then you can measure whether the two ends of the coil are connected to the shaft by connecting the rotor coils in series (but the brightness of the small bulb is slightly dimmer than when the measurement track is connected to the power supply, demonstrating Ohm's law).

Pictures of a knight and a horse are pasted on both sides of the rotor frame, and when the rotor rolls on the track, we can observe that the rider is already riding on the horse (we can also demonstrate the visual persistence experiments such as horse running and chicken pecking rice).

Counterweight experiment, principle experiment of electric fan,

light recombination experiments, etc.

The rotational kinetic energy and the gravitational potential energy are exchanged with each other, so that we can complete ten different experiments with the "motor casing".

Small hole imaging: Use a paper cup to cut a small hole in the bottom: any shape. Tie the rim of the cup with a plastic cloth with a leather case. There will be an image on the plastic sheet that can be seen through empty energy.

1. Take two identical small beakers (150 ml), fill them with water, put beaker A on the iron frame table, and put beaker B on the wooden block, so that the water surface in the two beakers is kept on the same level and grinded closed.

2. Insert two siphons, one long and one short, filled with water into two beakers. The siphon is made of ordinary thin glass tubes heated and bent on an alcohol lamp.

3. Add a few drops of red ink to the burning cup B and stir well. Ryo and prepare the alcohol lamp on the iron stand.

4. Light the alcohol lamp to heat beaker A, and after a while, you can see that the red water in beaker B flows into beaker B continuously, and finally the two cups of water turn red. At the same time, when you touch beaker B with your hand, the water in beaker B also becomes hot, indicating that there is convection between the two cups of hot and cold water.

I'm here to help you, a student who loves to learn.

Equipment: electric kettle, water, miniature ceiling fan, crystal diode lamp, power supply, method: 1. Fill the electric kettle with an appropriate amount of water;

2. Fix the miniature electric fan at the appropriate position above the spout of the kettle;

3. Connect the crystal diode lamp at the micro fan plug;

4. Plug the electric kettle into the power supply.

Phenomenon: After the water boils, the miniature ceiling fan rotates the crystal diode lamp and emits light.

Principle: The water vapor generated after the water boils pushes the fan blades to rotate, and the fan blades rotate to drive the motor to generate electricity in turn, and light the lamp to emit light.

Substance: electrical energy – internal energy – mechanical energy – electrical energy – light energy.

Finally, I wish you the best of luck!

Diode, check the information yourself, it's very simple.

A villain who knows martial arts.

Materials: old brush holders, colored electric paper, black buttons, red wool thread, nylon thread, plywood or horse dung paper, paints, paste, saws, drills, scissors, pliers.

1.Find one or two discarded brush sticks and cut them into 8 sections, each centimeter-long, with a sawFind a thicker barrel, saw it into a 3 cm section, and drill two small holes in a third of the way.

3.Paste these small bamboo joints with colored electric paper, and draw the face of the villain in the upper third of the thick joints. 4.

with two black buttons for the feet of the villain; Then use a large button or cut a round piece of cardboard paper and stick it to the top of the thick section to make a hat, and stick a little red wool in the middle of the top of the hat to make a hat. 5.Bend one end of a wire into a small circle for your right hand and spear; Then use the wire to bend a small circle for the left hand, 6

Use a nylon thread to thread the slubs together as in step 3.

How to playFind a piece of plywood or horse manure paper, make a long slit in the middle of the board (vertically and horizontally), place it at the crack of the table, thread the thread under the villain into the board seam, and manipulate the nylon thread with both hands from below, and the villain can move. Hold the line with both hands, loosen and tighten, and the villain can bow down together, raise his hands and bend over; Pull left and right, and the villain can move sideways. If you manipulate the law well, this villain who practices martial arts will use all kinds of tricks to make you appreciate his "superb" martial arts.

Note: If you can't find a suitable old brush barrel, you can also replace it with another perforated sleeve, or use kraft paper strips to coat the paste and roll it on the wire to make your own cardboard tube.

Microphone. Material: 1 line, 2 paper cups, and 1 hole in each paper cup. I put a thread into two holes, and each hole is separated by one knot and it is completed. (Straighten the line.) ）

There are a lot of them in the province, such as the following one:

1 Cut a toothpaste box out of it and put it into a mirror at a 45-degree angle to the wall of the box. (Behind the mirror, you can make a 45-degree right-angled triangle cushion to be more stable).

2 Cut a hole in the top of the other toothpaste box.

3 Assemble the toothpaste boxes together.

4 A periscope is ready.

Find out about the books.

To make a periscope, you only need two small square mirrors of the same size and a piece of cardboard. If your small mirror is ten centimeters long and seven centimeters wide, then you should prepare a piece of cardboard with a width of 4 7 = 28 centimeters. The length of the cardboard can be decided for yourself according to the conditions.

The cardboard is longer, and the periscope can be made taller.

Three parallel lines were drawn on the cardboard, each with a distance of seven centimeters, as shown in the diagram. Cut off the blacked-out parts. Use a knife to make a mark along the dotted line (be careful not to cut through).

Then, fold it around the table to make a rectangular box and glue it with kraft paper.

Glue the small mirror with white tape as shown in the picture below (so that the angle between the small mirror and the long carton is equal to 45°). Two small mirrors are aligned in parallel. In this way, a periscope was made.

Musical Instruments: Strap a few rubber bands to the box! That's what I did. o(∩_o~

We first prepare the ingredients, empty drink bottles, foam fruit nets, and a glass marble, etc., and then we can get started.

We cut out the top half of the prepared empty bottle, divide the cut part into 8 parts, cut it to the neck of the bottle with scissors, and cut each part into the same large petals.

Then we put the foam mesh cover on the outside of the bottle, then we fasten it with a rubber band, and then we put another foam mesh on the glass marble and plug the bottle mouth, plug it tightly and expose about a centimeter.

We cut half of the table tennis ball, then cover half of the ball at the mouth of the bottle, and then trim the four sides into a whisker, the mouth of the bottle is fixed with a rubber band, and it is finished after beautifying it.

Summary 1 11To prepare the ingredients, cut out the top half of the empty bottle and divide the cut part into 8 parts.

2.The foam mesh sleeve is placed on the outside of the bottle and is secured with a rubber band, and the other foam mesh is placed on the glass marble sheet.

3.For half of the table tennis ball, cover half of the ball at the mouth of the bottle, then trim the four sides into a whisker shape and fix it.

Periscope; Use a toothpaste box to make two horizontal flat mirrors at both ends.

Small musical instruments: syringes Depending on the height of the free movement of the fader, the pitch can be changed.