1. Fill in the blank: (65438+ 0 for each blank, ***30)
1, in order to make the flute sound, you must blow hard, so that you can _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.
2. The propagation speed of sound in the air at 15℃ is _ _ _ _ _ _ _ m/s. On summer nights, a dazzling lightning thunders for 8 seconds and then stops for 5 seconds. The discharge cloud is _ _ _ _ _ _ meters away from you.
3. In order to study how sound propagates, Xiaoli explored with the device shown in figure 1. Put the sounding alarm clock in the glass cover, and put the soft foam plastic between the alarm clock and the glass cover base. Gradually draw the air out of the hood, and the alarm clock she heard gradually became smaller. Further reasoning can lead to the conclusion that sound cannot spread in _ _ _ _ _ _ _.
4. As shown in Figure 2, it is a waveform diagram of the sound played by Xiao Ming through the same oscilloscope with his flute and erhu. As for these two tones, your understanding is _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
There is a goldfish bowl in Xiaoming's home. When Xiao Ming knocked on the table, the goldfish in the bowl was immediately frightened.
(1) There are four ways to judge the sound wave propagation path received by fish: a. Air → water → fish; B. dining table → water → fish; C. dining table → air → water → fish; D. dining table → fish tank → water → fish. Where _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ refers to
(2) If there is only one small fish in the fish tank (as shown in Figure 3), eyes can observe two fish from point A, one fish becomes shallower and the other fish becomes bigger. The former is _ _ _ _ _ _ _ image (fill in "real" or "virtual"); The latter is the _ _ _ _ _ _ _ _ _ image (filled with "real" or "imaginary") formed by the equivalent convex lens on the _ _ _ _ _ _ _ _ _ _ _ side of the fish tank.
6. Sunlight can be divided into _ _ _ _ _ _ _ _ _ _ ribbons through a prism, which is called the _ _ _ _ _ _ phenomenon of light.
We saw the sun when it was still below the horizon. This is because _ _ _ _ _ _ makes the light bend. This phenomenon shows that light only travels in a straight line in _ _ _ _ _ _ _ _.
8. The color of transparent objects is determined by _ _ _ _ _ _ _ _ _ _, and the color of white objects is determined by _ _ _ _ _ _ _ _ _ _.
9. On the night after the rain, people walk in the moonlight. In order not to step into the puddle, people summarize it according to the laws of specular reflection and diffuse reflection. When walking against the moonlight, there is water in _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _. (optional "light" and "dark")
10. Every desk lamp we use for study and work has a lampshade (as shown in Figure 4). The function of this lampshade is to use the principle of _ _ _ _ _ _ _ _ _ _, and the inner surface of the lampshade should be as _ _ _ _ _ _ _ _ _ as possible. (Select Smooth or Rough).
A person with a height of 1 1 and a height of 1.7m stands 3m in front of a vertical plane mirror of1m. His image height in the mirror _ _ _ _ _ _ _ _ _ m, and his image is _ _ _ _ _ _ m away from him.
12. When examining the ear canal, the doctor should wear a _ _ _ _ _ _ _ _ _ mirror with a hole in the middle, and there are _ _ _ _ _ _ _ _ _ _ _ _ _ holes in the mirror.
13, the fog light of the car is _ _ _ _ _ _ _ _. The ultraviolet ray is _ _ _ _ _ _ _ (select "visible" or "invisible"). Write an example of ultraviolet lamp for human use: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.
14. Some residents put "cat's eyes" on the gate. People in the room can clearly see the narrow outdoor scenery near the "cat's eye", but they can't see the room from the outside. As shown in Figure 5, there are different types of lenses. You chose _ _ _ _ _ _ _ _ as the "cat's eye" lens. The observation range from indoor to outdoor is _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Second, multiple-choice questions (2 points for each small question, ***28 points)
15, you can hear a pleasant sound by plucking the strings with your hands. At this time, the object as the sound source is ().
A, finger b, string c, air d, string column
16. In the story of The Little White Rabbit and Grandma Wolf, the little white rabbit can tell that it is not her grandmother when she goes out, mainly based on her voice ().
A, loudness b, timbre c, tone d, frequency
17. In order to detect the activities of enemy cavalry as early as possible, scouts often put their ears to the ground to listen, so that they can judge whether there are enemy cavalry nearby. The following explanation is wrong ().
The horseshoe sticks to the ground, making the ground vibrate and make a sound.
Sound can travel by land.
Land travels faster than air.
Horseshoe can't be heard in the air.
18, Wuxi municipal government decided to ban motorcycles from carrying passengers in urban areas from June last year 10. From the noise point of view, do you think ()
A, reduce the propagation distance of noise b, and reduce the number of noise sources.
C, reduce the propagation speed of noise d, and eliminate noise.
19, the following objects do not belong to the light source is ()
A, the screen of the movie being played b, the TV being played
C, jellyfish D, Big Dipper
20, the following statement is correct ()
The propagation speed of light is 3× 108 m/s.
Light always travels in a straight line.
Light-year is a common unit of time in astronomy.
When light is reflected, the propagation direction changes and the propagation speed remains the same.
2 1, the sunlight is 24 with the horizontal plane. To make the reflected light propagate along the horizontal direction, the included angle between the plane mirror and the horizontal direction should be ().
a、24 B、 12
C, 150 D, 78 or 12.
22, the light path diagram shown in figure 6 is correct ().
23, as shown in figure 7, with a flashlight to illuminate the image in the plane mirror, the observed image is much brighter than the original, the reason is ().
A, the light shines on the image, so it will be bright.
B. The mirror is brighter than before, so the image is brighter.
C. When light is reflected on an object, the object becomes brighter, so the image becomes brighter.
D, there is light irradiation, which is more convenient for observation, so it feels brighter.
24. In the fable of "the monkey catches the moon" (as shown in Figure 8), the monkey sees the moon in the well and tries to catch it. And I didn't catch anything. Regarding the distance between the moon and water in water, the following statement is correct ().
The moon is on the water.
The moon is as deep as a well.
Equal to the distance from the moon in the sky to the water surface.
The distance from the monkey's eyes to the water surface is equal.
25, a convex lens with a focal length of10cm, when the object gradually moves from 30cm to 20cm away from the lens ().
The image becomes smaller and the image distance becomes larger.
The larger the image, the larger the image distance.
The image first becomes smaller and then larger, and the image distance keeps increasing.
The image is getting bigger and bigger, and the image distance first decreases and then increases.
26. Xiao Ming and Xiao Hong used the same camera to take pictures of Xiao Qiang with the same focal length, and the developed negatives were (a) and (b) in Figure 9 respectively, so ().
A Xiaohong should make the image on the negative as big as Xiaoming's, and then narrow the distance between the lens and the negative after Xiaohong moves.
Xiaoming and Xiaohong are at the same distance from Xiao Qiang.
C Xiaohong wants to move the image on the negative to the same size as Xiaoming, and then increase the distance between the lens and the negative.
D. Xiaohong is near Xiao Qiang.
27, which of the following groups of connections is wrong ()
28. Xiaoming made a model camera with a film, two retractable paper tubes and a convex lens, and used it to observe the scenery around us. There are several sayings: (1) The image on the film is inverted. (2) When observing, aim the film at the scene and keep your eyes close to the convex lens. (3) When observing the distant scenery to the nearby scenery, the paper tube should be lengthened. (4) During the day, we looked at the pictures in the classroom with our own cameras on the balcony and found that the pictures were very dark. These four statements are correct ()
a 、( 1)2)3)4)B 、( 1)2)4)C 、( 1)3)D 、( 1)3)4)
Three. Drawing problem: (3 points for each drawing, *** 12 points)
29. Complete the light path diagram in Figure 10, with I as the incident angle and R as the reflection angle.
30. In figure 1 1, the image of an object in a plane mirror is made according to the imaging characteristics of the plane mirror.
There are two reflected rays in the figure 3 1. Please draw the starting point s and its image s'
32. A frog lies at point P in the middle of a dry well, and its field of vision can be seen, as shown in figure (a). When it rains heavily, the well is full of water. If the frog is still at point P, its vision will change. Please use the light path diagram in Figure (b) to determine the approximate range of frog's visual field change, and indicate it with a shadow.
Four, experimental inquiry questions (6 points for each small question, ***30 points)
33. Xiao Fang took a photo in the suburbs with a digital camera, as shown in figure 14. Please observe the scene in the photo and point out a physical phenomenon: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _;
The physical knowledge involved in this phenomenon is: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.
In the inquiry experiment of sound propagation, Xiaohong and Xiao Fang did the following two inquiry experiments:
Step ① Put two tables tightly together. One student tapped on the desktop, and the other student put his ear to another desktop to listen to the sound.
Step 2: Keep two adjacent tables away from a small gap, and then repeat the first step to compare the sound.
(1) Please help them analyze and fill in the experimental phenomena and analysis results in the form.
The size of the sound
What does sound mainly spread by?
When two tables are next to each other
When there is a small gap between two tables
(2) Xiaohong thinks: Can liquid spread sound? She found a water container from home. What other equipment does she need? Please help her figure out the method of the experiment.
When "studying the imaging characteristics of plane mirror", Xiao Ming replaced the plane mirror with a glass plate. He used the same Go as an imaging object and an image-seeking object.
(1) Xiaoming replaced the flat mirror with a glass plate for _ _ _ _ _ _ _ _ _ _.
(2) On the same side of the glass plate, Xiao Ming saw two images of the same Go player through the glass plate. And the reason for this phenomenon is _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
(3)M is a square disk placed on the desktop, and N is a glass plate perpendicular to the disk surface. Xiao Ming put two black flags on the plate, and the image they formed in the glass plate should be () in the picture.
Many common items in daily life can be used to do small physical experiments, such as scales, pencils, white paper, steel rulers, reading glasses, glass plates, water and so on. Choose equipment to do two small experiments, and briefly write the experimental process to explain the physical principles.
Experimental device
Experimental process
The physical principles expressed.
37. It's sunny on Sunday. Xiao Wang and Xiao Zhang are doing their homework at Xiao Wang's house. Xiao Zhang feels very dazzling. Look at this room. No strong light source. They followed the light and found a small flat mirror on the ground below the building. This is the mystery! Xiao Wang and Xiao Zhang became interested. They immediately made a research project and began to design experiments and operate them.
What do you think their research topic should be? _________________________________.
They thought for a moment and immediately found some experimental equipment to operate.
Step A: Place a piece of creased cardboard flat on a horizontal desktop, and vertically place a small flat mirror as a reflecting surface. The light emitted by a small laser flashlight obliquely shines on the O point on the plane mirror along the cardboard, and a stroke line is used instead of light to leave traces on the cardboard (as shown in Figure 16). The angle between the reflected light and the crease and the angle between the incident light and the crease were measured with a protractor, and it was found that they were equal.
Step b: Fold one half plane M of the cardboard below the edge of the table, and then shoot at point O obliquely along the other cardboard plane N with laser, and find that there is no reflected light on the plane M. ..
Please analyze their experimental steps, and at least one conclusion can be drawn: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.
What do you think are the shortcomings of their experiment: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ (at least write a little)
Scoring criteria and reference answers
fill-in-the-blank question
1, air vibration 2,340 2720 3, vacuum 4, flute
5.( 1)D (2) virtual right virtual 6, seven dispersion 7, refraction of light in the same homogeneous medium 8. The color of transmitted light is red 9, bright and dark 10, smooth reflection 1 1, 1.7 6.
12, concave convergence 13, yellow invisible banknote inspection, etc. 14, e is large.
Multiple choice
15、B 16、B 17、D 18、B 19、A 20、D 2 1、D
22、B 23、C 24、C 25、B 26、C 27、B 28、D
Drawing questions (as shown below)
Fourth, experimental inquiry questions
33, the reflection of plane mirror imaging light
34.( 1) The larger desk (solid) becomes smaller air.
(2) Tip: Find a sound source and put it into the water, so that people's ears are close to the container wall to listen.
35.( 1) Convenient location for finding and portrait (2) Both sides of the glass reflect at the same time, and each side forms an image (3) b.
36. Examples:
Experimental device
Experimental process
The physical principle you want to express.
Division rule
Press one end of the scale on the desk, and move the scale with different force at the other end to listen to different loudness.
Relationship between loudness and amplitude
White paper and reading glasses
Sunlight shines on reading glasses, and a brightest and smallest light spot is found on the other side of the white paper.
A convex lens can condense light.
37. What is the law of light reflection?
The reflection angle is equal to the incident angle (or the reflected light and the incident light are in the same plane; Reflected light and incident light are on both sides of the normal)
There are too few experiments. Agree 0| Comment
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2010-1-1520:16mmkmkmk123456 | 5.
Not approved 0| Comment 2010-1-2612: 34 Yellow croaker 12 | Grade II.
Tell you to review the outline; 1. Generation and spread of sound
The generator is vibrating-experiment; Sound travels through media-media: all solids, liquids and gases; Vacuum can't transmit sound.
Sound speed-the sound speed in the air (about 340m/s); Velocity in general solid >: velocity in liquid >: velocity in gas; The speed of sound increases with the increase of temperature.
Echo-Time and distance required for echo; App application
Calculation-Combined with Travel Problem
2. Tone, loudness and timbre
Objective quantities-frequency (pay attention to the range of human hearing and vocalization) and amplitude.
Subjective quantities-pitch and loudness (meaning high or low); Factors affecting loudness: amplitude, distance and dispersion.
Timbre-function; The timbre is determined by the vocal body itself.
3. Harm and control of noise
Noise-noise in physics and life (physics-irregular vibration, life-sounds that affect work, study and rest); Noise level: dB (0dB-only causing hearing); Methods to reduce noise (at the sound source, during propagation, at the human ear); Four major pollutions (air pollution, water pollution, solid waste pollution and noise pollution)
1. Light source-torches, candles, electric lights, stars (the moon and planets are not light sources).
2. Linear propagation of light
Linear propagation (uniformity) of light conditions; Can spread in vacuum; Phenomena (laser collimation, shadow, pinhole imaging P78 and light spots under trees, solar and lunar eclipses); The speed of light in vacuum (3× 10[sup]8[/sup]m/s), and the light year is the unit of length.
3. Light reflection
Law of reflection-three lines * * * surface; Separate the two sides; Equal angle; The optical path is reversible (note that the narrative order should conform to the causal relationship)
Specular reflection and diffuse reflection-every ray conforms to the law of reflection (phenomenon explanation: polished metal surface, calm water surface, ice surface and glass surface can all be regarded as mirrors; Others are regarded as rough surfaces, P79 Figure 5-40; Should be answered according to the phenomenon)
4. Flat mirror
Plane mirror imaging-regularity (isometric, isometric, upright, virtual image); The range of visible (invisible) images; periscope
5. Drawing-Drawing according to relevant laws.
1. Refraction of light
Refraction-definition (... direction usually changes); Law of refraction (three lines * * * plane, two sides, different angles; The optical path is reversible; Pay attention to the narrative order to conform to the causal relationship); Phenomenon explanation (shallow fish in water, bent chopsticks in water, mirage, etc.). )
2. The comprehensive problem of light propagation
Pay attention to distinguish between refracted light and reflected light; Pay attention to distinguish between different shadows and images.
camera lens
Terminology of lenses-principal optical axis, optical center, focal length and focal point (method of measuring focal length)
The effect of convex lens and concave lens on light-the difference between "convergent light" and "convergent light": "convergent light" refers to the light that can converge to a point, and "convergent light" refers to the light that is closer to the main optical axis after passing through the convex lens than before)
Principle of multi-prism combined lens; The light is refracted on both sides of the lens.
Changed convex lenses-glass balls, round bottles of water, water drops on glass plates, etc.
Black box problem
4. Convex lens imaging
Three kinds of special light (passing through the center of light-the direction is unchanged; Parallel to the main optical axis-optical center; Light passing through the optical center-parallel to the main optical axis); The relationship between image distance/image size/virtual reality/upside down and object distance; The speed of image movement (based on: optical path diagram); practical application
1. thermometer
Thermometer-material, principle and measuring range of common thermometer (thermometer: 35 ~ 42℃; Thermometer: -20~50℃)
How to use-the structure and use of thermometer (necking part; Function and principle of throwing thermometer; The consequences of not throwing-only affecting low temperature measurement), the use of thermometer (pay attention to the selection of range); Calibrate the thermometer; Reading (generally you can't leave the object when reading)
Temperature scale-centigrade scale, thermodynamic temperature scale and conversion; Absolute zero; Ordinary temperature
2. State transformation
Melting and solidification-experimental device (water bath heating); Common crystals and amorphous; Melting point and freezing point; picture
Vaporization-evaporation; Factors affecting evaporation rate; Boiling experimental device; The connection and difference between evaporation and boiling (both evaporation; Intensity, occurrence conditions, etc. ); Use of alcohol lamp (refer to chemistry)
Liquefaction-two ways (cooling will definitely liquefy the gas; Compression can liquefy gas)
Sublimation and Sublimation-Examples
3. Heat transfer in the change of state of matter
Heat absorption-solid → liquid → gas (even if the temperature is constant, there is heat transfer); Exothermic gas → liquid → solid
4. Others
Phenomenon explanation-for example: P3 Figure 0-3, refrigerator principles such as boiling water in paper pot, "white gas" and water droplets (liquefaction) on glass, frost, dew, clothes drying (evaporation sublimation) and camphor; Heat calculation in the change of material state; Pay attention to the writing of nouns (steam, gas; Dissolve, melt, melt; China, China; Coagulation) and letters (t and t; C and k)
Chapter IV Circuits
1. Two kinds of triboelectrification charges
Static electricity-the judgment of charge type; Electroscope structure (P45 diagram); Electricity (unit: coulomb c)
Material microstructure-atomic structure (can be compared with the concept of atom in chemistry); The cause of triboelectrification (electron transfer outside the nucleus)
2. The corresponding circuit concept
Current (and direction: the direction of positive charge movement); Power supply; Conductors and insulators; Series and parallel connection; Free charge and direction of motion in the circuit; Circuit diagram; Paths, open circuits and short circuits; Ordinary circuit (corridor circuit; Refrigerator Circuit: Volume I P60 Figure 4- 18)
Judgment of equivalent circuit-first remove the ammeter/voltmeter (ammeter: short circuit; Voltmeter: open circuit) before making a judgment.
1. Definition, unit (unit symbol), meaning and conversion of each physical quantity (I, U, R, P)
Usage of ammeter and voltmeter (range and range selection, series and parallel connection, positive and negative poles, whether they can be directly connected to both ends of power supply) and their structures.
2. Measurement of resistance (basic methods and changes); Factors affecting resistance; Structure and use of sliding rheostat (P94 Figure 7-7); Use and reading of variable resistance box (P95 Figure 7-9, 7-10; Potentiometer); Deformation of sliding rheostat (e.g. p 10 1 Figure 7- 19)
3. Ohm's law and deformation (pay attention to the physical meaning)
4. Series-parallel current, voltage and resistance formulas (note the conditions. For example, power is directly proportional to resistance in series connection and inversely proportional to resistance in parallel connection; Joule's law only applies to pure resistance circuits, and it applies to all circuits when calculating heat.
Common conclusion (each proportional formula; When the resistance of sliding rheostat changes, the changes of each physical quantity in the circuit-pay attention to the derivation order)
5. Electricity-W = UIT = UQ; Electric energy meter and measuring power with electric energy meter (P130);
Electrical nameplate; Working time coefficient of refrigerator (P 130)
6. Electrical calculation-① Draw equivalent circuit diagram (draw several pictures for several states); (2) Find out the equivalence relation and the proportional relation according to the series connection and parallel connection; ③ Solution (note that current, voltage and electric power should be in the same state) Agree 1| Comment 2010-1-2713: 03 Enthusiastic users.
The final answer to the formative examination paper of physical English in Grade 8, Grade 2, 2008-2009;
answer
The title is11213141516171819 20.
answer
8th grade physics answers in 2008-2009 school year.
I. Multiple choice questions
The title is 1 23455 6789 10.
Answer A D C C B B A C D C
The title is11213141516171819 20.
Answer C A D D C B B D A C
Step 2 fill in the blanks
1. 1 1
2.5
3. Reflection and refraction
4.ab cd d
5.B -8
6.38
7. Crystal 0
8. Compressed volume
9. Electrostatic attraction of light and small objects
10.0.2
1 1. The same fee.
12. Power switch
13.( 1)S2 1 S3(2) 1 S3 S2
8th grade final exam in the first semester of 2008-2009 school year.
Physics examination questions
Examination paper number of this examination room
Attention to candidates: 1, the examination time is 90 minutes.
2. Tell you to review the outline; 1. Generation and spread of sound
The generator is vibrating-experiment; Sound travels through media-media: all solids, liquids and gases; Vacuum can't transmit sound.
Sound speed-the sound speed in the air (about 340m/s); Velocity in general solid >: velocity in liquid >: velocity in gas; The speed of sound increases with the increase of temperature.
Echo-Time and distance required for echo; App application
Calculation-Combined with Travel Problem
2. Tone, loudness and timbre
Objective quantities-frequency (pay attention to the range of human hearing and vocalization) and amplitude.
Subjective quantities-pitch and loudness (meaning high or low); Factors affecting loudness: amplitude, distance and dispersion.
Timbre-function; The timbre is determined by the vocal body itself.
3. Harm and control of noise
Noise-noise in physics and life (physics-irregular vibration, life-sounds that affect work, study and rest); Noise level: dB (0dB-only causing hearing); Methods to reduce noise (at the sound source, during propagation, at the human ear); Four major pollutions (air pollution, water pollution, solid waste pollution and noise pollution)
1. Light source-torches, candles, electric lights, stars (the moon and planets are not light sources).
2. Linear propagation of light
Linear propagation (uniformity) of light conditions; Can spread in vacuum; Phenomena (laser collimation, shadow, pinhole imaging P78 and light spots under trees, solar and lunar eclipses); The speed of light in vacuum (3× 10[sup]8[/sup]m/s), and the light year is the unit of length.
3. Light reflection
Law of reflection-three lines * * * surface; Separate the two sides; Equal angle; The optical path is reversible (note that the narrative order should conform to the causal relationship)
Specular reflection and diffuse reflection-every ray conforms to the law of reflection (phenomenon explanation: polished metal surface, calm water surface, ice surface and glass surface can all be regarded as mirrors; Others are regarded as rough surfaces, P79 Figure 5-40; Should be answered according to the phenomenon)
4. Flat mirror
Plane mirror imaging-regularity (isometric, isometric, upright, virtual image); The range of visible (invisible) images; periscope
5. Drawing-Drawing according to relevant laws.
1. Refraction of light
Refraction-definition (... direction usually changes); Law of refraction (three lines * * * plane, two sides, different angles; The optical path is reversible; Pay attention to the narrative order to conform to the causal relationship); Phenomenon explanation (shallow fish in water, bent chopsticks in water, mirage, etc.). )
2. The comprehensive problem of light propagation
Pay attention to distinguish between refracted light and reflected light; Pay attention to distinguish between different shadows and images.
camera lens
Terminology of lenses-principal optical axis, optical center, focal length and focal point (method of measuring focal length)
The effect of convex lens and concave lens on light-the difference between "convergent light" and "convergent light": "convergent light" refers to the light that can converge to a point, and "convergent light" refers to the light that is closer to the main optical axis after passing through the convex lens than before)
Principle of multi-prism combined lens; The light is refracted on both sides of the lens.
Changed convex lenses-glass balls, round bottles of water, water drops on glass plates, etc.
Black box problem
4. Convex lens imaging
Three kinds of special light (passing through the center of light-the direction is unchanged; Parallel to the main optical axis-optical center; Light passing through the optical center-parallel to the main optical axis); The relationship between image distance/image size/virtual reality/upside down and object distance; The speed of image movement (based on: optical path diagram); practical application
1. thermometer
Thermometer-material, principle and measuring range of common thermometer (thermometer: 35 ~ 42℃; Thermometer: -20~50℃)
How to use-the structure and use of thermometer (necking part; Function and principle of throwing thermometer; The consequences of not throwing-only affecting low temperature measurement), the use of thermometer (pay attention to the selection of range); Calibrate the thermometer; Reading (generally you can't leave the object when reading)
Temperature scale-centigrade scale, thermodynamic temperature scale and conversion; Absolute zero; Ordinary temperature
2. State transformation
Melting and solidification-experimental device (water bath heating); Common crystals and amorphous; Melting point and freezing point; picture
Vaporization-evaporation; Factors affecting evaporation rate; Boiling experimental device; The connection and difference between evaporation and boiling (both evaporation; Intensity, occurrence conditions, etc. ); Use of alcohol lamp (refer to chemistry)
Liquefaction-two ways (cooling will definitely liquefy the gas; Compression can liquefy gas)
Sublimation and Sublimation-Examples
3. Heat transfer in the change of state of matter
Heat absorption-solid → liquid → gas (even if the temperature is constant, there is heat transfer); Exothermic gas → liquid → solid
4. Others
Phenomenon explanation-for example: P3 Figure 0-3, refrigerator principles such as boiling water in paper pot, "white gas" and water droplets (liquefaction) on glass, frost, dew, clothes drying (evaporation sublimation) and camphor; Heat calculation in the change of material state; Pay attention to the writing of nouns (steam, gas; Dissolve, melt, melt; China, China; Coagulation) and letters (t and t; C and k)
Chapter IV Circuits
1. Two kinds of triboelectrification charges
Static electricity-the judgment of charge type; Electroscope structure (P45 diagram); Electricity (unit: coulomb c)
Material microstructure-atomic structure (can be compared with the concept of atom in chemistry); The cause of triboelectrification (electron transfer outside the nucleus)
2. The corresponding circuit concept
Current (and direction: the direction of positive charge movement); Power supply; Conductors and insulators; Series and parallel connection; Free charge and direction of motion in the circuit; Circuit diagram; Paths, open circuits and short circuits; Ordinary circuit (corridor circuit; Refrigerator Circuit: Volume I P60 Figure 4- 18)
Judgment of equivalent circuit-first remove the ammeter/voltmeter (ammeter: short circuit; Voltmeter: open circuit) before making a judgment.
1. Definition, unit (unit symbol), meaning and conversion of each physical quantity (I, U, R, P)
Usage of ammeter and voltmeter (range and range selection, series and parallel connection, positive and negative poles, whether they can be directly connected to both ends of power supply) and their structures.
2. Measurement of resistance (basic methods and changes); Factors affecting resistance; Structure and use of sliding rheostat (P94 Figure 7-7); Use and reading of variable resistance box (P95 Figure 7-9, 7-10; Potentiometer); Deformation of sliding rheostat (e.g. p 10 1 Figure 7- 19)
3. Ohm's law and deformation (pay attention to the physical meaning)
4. Series-parallel current, voltage, resistance)