Many teaching contents in the new junior high school physics textbook,
Is through
"Scientific inquiry" activity learning,
The students are studying classic works.
Experience the fun of learning science in the process of exploring science,
Master scientific methods,
Feel the knowledge of physics,
So as to form a good family
Learning attitude and values.
however
At present, the experimental equipment of most junior middle schools, especially rural schools, can not completely match the new textbooks.
The limited equipment in the laboratory can't meet the needs of the new curriculum.
Therefore,
Advocate the use of readily available items around you for experimental exploration.
Research activities,
Not only can the problem of insufficient experimental equipment be solved or alleviated,
It can also bring physics closer to life,
Cultivate students
It is of great significance for curriculum reform to truly feel the close connection between science and daily life.
This article will introduce the author's past teaching practice,
Drive students to skillfully use daily necessities and carefully develop them.
Ingenious conception
The experimental exploration cases of physics teaching AIDS and learning tools are discussed, and the methods and ways to develop and utilize experimental resources are discussed.
First of all, the simplest pump
Experimental materials are available at any time.
It's everywhere,
As long as we pay attention everywhere,
Good at discovery,
Many things are handy in daily life.
All imported articles can be a good resource for us to develop experiments.
Once I had a bad cold,
Lying in a hospital bed,
When I saw the nurse carrying a syringe and disposable plastic for intravenous injection,
When the water pipe came,
It suddenly occurred to me:
If only these materials could be used to make physics teaching AIDS,
I think hard.
Two days later, when I was discharged from the hospital, a teaching aid that won the second prize in the province was born.
draw
1
Cut off two thick sections of disposable plastic hose for intravenous injection.
(as shown in the figure.
A
and
B
)
A
There is a port at both ends, the upper port is the water outlet and the lower port is the water inlet.
B
There are two ready-made ports at the upper end and one at the lower end.
Mouth.
will
B
The port at the upper end is the same as
A
The low water inlet is connecte,
The other port is connected with a syringe,
then
B
Lower entrance
Put it in water and separate it in advance.
A
.
B
Put a small steel ball in it, so it becomes the simplest piston pump.
Machine.
Repeatedly twitching the piston of the syringe,
Water will flow from
A
The water outlet keeps flowing out.
because
A
.
B
Is transparent,
Students can clearly see the movement of the small steel ball in the hose when pumping water (that is, the opening and closing of the piston valve).
Judging from the materials of this teaching aid,
I understand a truth:
There are many things around us that can be used for experiments.
Yes,
The available experimental resources are very rich,
What we lack is not resources,
But to discover the insight and design reality of resources.
Wisdom of experience.
Although the method of developing experimental resources,
There are various development methods,
But the most valuable thing is innovation.
Consciousness and thought.
Second, very magical optical instruments.
Everything common around us has been transformed.
Can evolve into interesting scientific experiments:
Two paper tubes are magically combined.
Together, they can be made into models such as cameras, slide projectors, telescopes and microscopes, and this can be vividly revealed.
four
Optical instrumental
Principle.
1
. Camera.
draw
2
Give the students a convex lens in advance (you can also use a magnifying glass or a telephoto lens instead).
Have them prepare two copies.
16
An open magazine is rolled into two hollow cylinders with different sizes and covered at one end of the smaller cylinder.
Translucent plastic film,
The convex lens is fixed at one end of the larger cylinder with adhesive tape,
Cover the small tube with plastic film
One end can be freely inserted into the vat, thus making the camera.
In class,
Please bring the above equipment with you.
Aim the convex lens on the vat at the bright scenery in the classroom or outside the window,
front
Move the small cylinder backwards,
The image distance is changed,
At this time,
Students can observe different scenery near and far,
And can be molded in a small tube.
Get a clear color image on film.
Here, "When enlarging or reducing an image, should the camera be close to or away from the scene?" "Should the black box be lengthened or shortened?"
These traditional teaching problems,
Can be operated by students themselves,
It is easy to be broken through in observation,
Feel what you have learned.
Knowledge is more vivid, credible and impressive than any description in any language.
2
Slide projector
The above device can also be skillfully modified into a slide projector: just put a translucent plastic film on the small tube.
Change to transparent plastic paper,
Draw a landscape on plastic paper
(or directly replace it with transparent plastic wrapping paper with patterns,
in fact
This is a ready-made slide)
Shine a flashlight on the open end of the small tube,
The back cover of a book can be placed on a white wall or vertically.
An enlarged color scene appears in the picture.
Similarly,
"How should I enlarge or reduce the image?" Students are watching such questions as "Why should slides be inserted backwards?"
It is easy to master in the exam, and students learn physics knowledge in the game.
three
Telescope.
In the slide projector device, students only need to change the plastic paper on the small tube into a plastic paper with a more convex focal length than the plastic paper on the large tube.
A convex lens with short focal length (used as an eyepiece) can be converted into a telescope, and the small tube can move back and forth in the large tube.
You can see that the distant objects are obviously getting closer.
four
. Microscope.
By changing the position of the objective lens, the eyepiece in the telescope device can be used as a microscope.
Most junior middle school laboratories do not have "regular" demonstration cameras, slide projectors, telescopes and microscopes.
Type,
There is no way for the whole class to operate it themselves.
Observe and understand the above teaching difficulties,
It is composed of two paper tubes.
Models can do this.
Experiment with the daily necessities above,
There are also the following advantages:
First of all, it can reduce the workload of teachers.
Because even a piece
A better city school,
It is also impossible for teachers to prepare teaching AIDS for students before each class.
Secondly,
Students can also use self-made learning tools to operate repeatedly after class.
Don't worry about damaging the instrument,
So that they can completely
Hands-on, brain, observe the whole process of the occurrence and development of physical phenomena, and repeatedly taste the physical principles.
Therefore, the author believes that,
Doing experiments based on ignorance is using
"general"
This instrument is a supplement and extension to the experiment.
Good for the environment
Our school is also suitable and has strong vitality.
Third, interesting electrostatic experiment.
Electrostatic experiments are always difficult to succeed,
How to design experiments skillfully,
Look for materials that are easily char,
Is the key to the success of the experiment.
1
Electrostatic induction experiment.
draw
three
Take a used ballpoint pen core, remove the copper nib and wash off the residual pen oil.
Clamp the center part of the refill flat with pliers, and make a small hole in the clamped part so that the nib of the copper pen can just be inserted into the small hole.
Take another sewing needle, and fix one end with a needle eye on a cork (hot water bottle stopper), with the needle tip facing upwards, and fix it on a ballpoint pen.
The copper nib on the core is sleeved on the needle tip and can rotate flexibly on the needle tip.
Because the needle tip in the device just abuts on the small ball with the copper pen tip,
So the rotation is very flexible.
Let the students use plain paper.
Rub one end of the ballpoint pen core on the bracket to make it charged,
Take an uncharged ballpoint pen core.
(or other uncharged objects)
Near the charging end of the refill on the bracket,
You will find that they will be sucked away soon,
This is the wonderful electrostatic induction phenomenon,
very
Fun.
2
Charge interaction experiment.
Two refills are wiped with paper, and one refill is placed in the copper nib on the needle tip.
Hold the other hand in your hand,
Let their charged ends be close to each other,
At this time, the refill on the needle tip will be pushed away by the refill in the hand.
exchange
The position of the two refills can get the same result, which shows that the interaction between them is mutual.
three
.
Same-charge repulsion experiment.
Ask the students to write a long paragraph.
20
Cm ordinary plastic bandage rope.
(used for packaging teaching materials)
Tie a knot at one end,
Repeatedly tearing into a plurality of thin plastic threads from the other end to the knotting end by hands,
Then flatten this bundle of plastic thread.
Spread it on the table, rub the plastic wire with your fingers (this is the friction trick of fast charging), and lift the plastic when your fingers are hot.
The knotted end of the wire,
At this time, you can be surprised to see the image of plastic wire.
"possessed"
Automatically expand,
This experiment vividly shows that
Like charges repel each other.
four
Experiments of different objects with different charges after rubbing.
Using this readily available plastic bandage rope, it also
It can be explained vividly that two different objects have different charges after rubbing.
This is impossible for laboratory instruments.
Of:
Use a student's organic plastic ruler or triangle to rub food on an ordinary thin plastic bag.
Keep the charged plastic ruler close to it.
Charged plastic wire,
You will see scattered plastic lines, and hold the plastic ruler tightly at once.
And use a charged thin plastic bag to get close to the plastic.
Silk, but you will see that the charged plastic thread spreads more widely and refuses to contact with plastic bags. This experiment can vividly illustrate:
When the organic plastic ruler rubs against the plastic bag, it will carry different charges.
If the silk in the laboratory rubs against the glass rod,
The charge on the silk will disappear immediately,
Here, plastic bags are used instead of silk
Using organic plastic ruler instead of glass rod can retain charge for a long time, and the experimental phenomenon is very obvious. It can be seen that a general
With a little creativity, an ordinary dressing rope can easily solve a big problem in teaching.
Use ready-made discarded school supplies,
Things around you,
Well-designed interesting experiments are very creative:
First of all,
Use a humble little copper pen, cleverly design a sensitive bracket device, and use carefully selected easily charged solids.
Testing materials makes the originally difficult experiment easy; Second, similar to simple, convenient and practical experiments, for
Students provide more practical opportunities,
It enables everyone to do classroom experiments.
In order to stimulate students to study physics
Strong interest has created favorable conditions for cultivating students' creative thinking ability.
Fourth, sensitive multi-purpose small magnetic needle
In daily life,
There are many things around us that can be used for experiments.
As big as a refrigerator,
As small as a ballpoint pen core,
Sewing needle,
Is an available experimental resource,
Through ingenious design,
You can give full play to the experimental work of daily necessities.
It can inspire students' thinking and stimulate their initiative and enthusiasm in learning.
draw
four
Inspired by the above sensitive bracket device, I still use the above small copper pen and ballpoint pen core, and I
Together, the students invented a sensitive and versatile small magnetic needle:
Use a ballpoint pen core to clean the pen oil of the copper nib,
Cut out a paragraph
1
Cm length
The ballpoint pen core is sleeved on the nib, and the magnetized sewing needle is heated by fire and passes through the top of the ballpoint pen core.
Take another sewing needle,
Fix one end on the cork with a pinhole.
(or foam)
Last/better/previous/last name
The copper nib is sleeved on the needle tip,
This makes an extremely sensitive small magnetic needle.
With it, students can do the following series of experiments:
1
. Compass.
In textbooks,
There are many ways to make compasses introduced in reference books.
But I think the compass made in this way
This is the simplest and most sensitive. When you move a small magnetic needle by hand, when it stops, one end points to the south and the other end points to the north immediately.
2
Experiment of interaction between magnetic poles.
Take a magnetized sewing needle and lean its two ends against one end of the small magnetic needle respectively.
Recently, we can see the phenomenon of mutual attraction or repulsion.
three
Oster experiment.
Because the small magnet is very sensitive to rotation, students can make Oster with old dry batteries.
Experiment.
four
Experiment of judging the polarity of solenoid.
draw
five
The solenoid shown in the picture is rolled into a cylinder with the student's homework.
Around the wire,
The two ends of the self-made electrified solenoid are respectively close to the small magnetic needle,
According to attraction or repulsion,
as soon as...
We can judge the polarities of the two magnetic poles of the solenoid, so as to master the right-handed rule skillfully in operation.
five
Experiment of judging magnetic field strength of solenoid.
Ask the students to use different rotation methods to insert the nail into the middle of the pipe.
Electromagnetic coil,
Close to the small magnetic needle,
Depending on the magnitude of the interaction force,
We can explore the magnetic field strength of solenoid and what.
Related factors.
This is an innovative experimental design.
Its outstanding feature lies in sewing needles with things around it.
Ballpoint pen refill
And wires,
This very sensitive and simple small magnetic needle and solenoid are made.
The manufacturing method is very simple,
Every student can
With self-control,
One thing is versatile,
A group of devices is combined,
It can solve the teaching content of magnetic phenomenon and current magnetic field.
A series of problems in class, many students can bring hands-on experiments in class.
So,
Not all physical experiments need special experimental instruments to complete.
Many daily lives around us.
Consumables can also complete the in-class experiments well and achieve very satisfactory results.
Five, wonderful optical experiment
Clever experimental design is not only reasonable in equipment application,
It should also include wonderful experimental methods,
Not just for the sake of
Can solve the problem,
But also can give people the enlightenment of intelligent methods needed to solve other problems through specific experiments.
under
This device is a good example.
It successfully solved the long-term puzzle of optical experiments,
Skilled
Successfully completed the following series of experiments.
draw
six
Take a cylindrical flat-bottomed transparent plastic box, seal it, make a round hole on the side, and put the box on the side.
On the bracket
(i.e. let the outer bottom face the reader)
Injecting half a box of water into the round hole on the upper side of the box body to a horizontal diameter,
draw
seven
Drop two drops of milk into the water,
Inject a proper amount of light smoke into the round hole,
Let the smoke fill the space above the water.
(Available waste)
The newspaper is rolled into a thin hollow paper tube.
Ignite one end of the paper tube,
Smoke discharged from the other end is sucked into the syringe by the syringe,
then
Inject it into the round hole on the box)
Plug the round hole with a rubber plug,
Draw the water surface and normal line on the outer bottom surface of the box,
In the box.
The edge of the auxiliary outsole is marked with an angle,
Irradiate that transparent box into the box from the outside with a toy laser pen,
You can see clear and bright red.
Light.
With the above equipment, we can explore:
(
1
Refraction of light obliquely incident from air into water. (
2
The refraction of light incident obliquely from water into the air.
(
three
Reversibility of light: remember the position of the original incident light and the original refracted light, and let the light go against the original refracted light.
Direction incidence,
At this time, the new refracted light will be recombined with the original incident light and emitted in the opposite direction.
This shows that the optical path is reversible.
Yes
(
four
) incident along the normal, the direction of refracted light remains unchanged.
(
six
Total reflection of light: when light obliquely enters the air from water.
When you are angry,
It can be seen that part of the light is refracted into the air,
Another part of the light is reflected back into the water,
Gradually increasing the incident angle,
You'll see wrinkles
The emitted light is farther and farther away from the normal, the brightness is weaker and weaker, but the reflected light is stronger and stronger. When the refraction angle reaches
90
At 0,
The refracted light disappears completely, resulting in total reflection. At this time, the critical angle can be read directly from the scale on the edge of the box.
The wonder of this experiment is that:
The incident angle can be changed at will;
Incident angle,
Reflection angle,
The angle of refraction can start from the edge of the plastic box.
Read directly along the target angle,
The refractive index can be calculated conveniently;
Let red be clearly displayed in a bright classroom.
Color light;
Students can imitate the above production methods.
The device consists of various small cylindrical boxes in daily life.
This experiment provides us with an example of using abundant waste materials in daily life to solve experimental problems.
Zaiguang
In the refraction experiment,
Usually put the light source in water,
Let the light shoot into the air from the water,
It's hard to do,
The experimental effect also
Not so good.
This experiment is ingeniously incident from the outside of the transparent box.
Easily solved this big problem,
And there is no extra light.
On the screen, you can read the angle directly from the edge of the box. Through the above examples, the author believes that although the cost of low-cost physical experiments is low,
The wisdom used is not low, the connotation is not low and the educational value is not low.
Over the years,
The author has carefully designed a large number of novel and unique teaching AIDS, and the daily necessities are handy.
Learning tools,
Won many times.
Won national, provincial and municipal awards and was invited to give lectures in various places. Last year, these local teaching AIDS were moved to the forum of Beijing Normal University for use by Beijing Normal University.
Works of Postgraduates Majoring in Physics Teaching Theory
Reform and Innovation of Physics Experiment Teaching in Middle School
Special lectures,
Won a lot of applause.
Using the existing daily necessities at hand, after a little processing, a simple, vivid and interesting physics teaching aid is designed.
Compared with conventional instruments,
Using these simple materials,
Close to life,
You don't need to spend a lot of time and energy to be accurate.
Prepare the experimental equipment,
In-class experiments that can be completed,
Every student's hands-on participation,
The experimental inquiry provides the necessary materials.
Foundation,
Greatly stimulated students' desire to learn,
Effectively stimulate students' learning motivation,
Enhance the learning experience process.
This is not only a powerful measure to solve the shortage of instruments,
Let students feel that physics is around them.
Make learning interesting,
At the same time, it will also develop students' intelligence factors such as observation ability, exploration ability, operation ability and innovation ability. So this pen
The author thinks that it is not only an expedient measure (a helpless move to solve the problem of insufficient instruments), but also suitable for doing experiments simply because of ignorance.
Schools with better conditions should become a development direction of the current new curriculum reform.