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; Application (less important)
Calculation-combined with travel problem (less important)
2. Tone, loudness and timbre (not very important, but remember the experiment of steel rule)
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 (less important)
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 sources-torches, candles, electric lights ... (The moon and planets are not light sources and are not very important)
2. Linear propagation of light
Linear propagation of light conditions; Can spread in vacuum; Phenomena (laser collimation, shadow, pinhole imaging, light spots under trees, solar eclipse, lunar eclipse); The speed of light in vacuum (3×108m/s)
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.
4. Flat mirror
Plane mirror imaging-regularity (isometric, isometric, upright, virtual image); The range of visible (invisible) images;
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
5. Scattering of light
The color of transparent objects is determined by transmitted colored light, while opaque objects are determined by reflected colored light.
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. ); Liquefaction with alcohol lamp (less important)-two ways (cooling temperature; Compressed volume)
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. Phenomenon explanation-Example: P3 Figure 0-3, boiling water in paper pot, "white gas" and water drops (liquefaction) on glass, frost, dew, clothes drying (evaporation sublimation), camphor, etc. Principle of refrigerator; Heat calculation in the change of material state; Pay attention to the writing of nouns 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; Electricity (unit: coulomb c)
; Friction electrification reason
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
1. Definition, unit (unit symbol), meaning and conversion of physical quantity I
The purpose of ammeter (range and range selection, series-parallel connection, positive and negative poles, whether it can be directly connected to both ends of power supply) and its structure.
It's very important: I summed up the methods of doing the problem, such as: judging whether to close the S… switch, L … and I … series or parallel. Grab a piece of paper, draw with a pencil, close the S switch, and draw the pen along the positive pole to the negative pole to see if it meets the requirements. There are still many people who think that the problem of Hua circuit is very difficult. In fact, you must first judge whether the electrical appliances are connected in series or in parallel, and draw the circuit. Don't draw switches and ammeters first, and then add switches and ammeters to the circuit according to the conditions. These methods once made me correct in a circuit problem in the exam. ) Take notes in Grade 8 of New Target English.
Unit 1-6 review
First, the language goal (language goal)
1. Talk about how often you do things.
2. Talk about your health. Make suggestions.
Talk about health topics and make suggestions.
3. Talk about future plans.
Talk about future plans.
4. Talk about how to get to the destination.
Talk about the way to get to a place.
5. Learn to make invitations, say yes to invitations and give reasons.
Learn to send, accept and reject invitations and give reasons.
6. Learn to talk about personal characteristics and how to compare people.
Learn to talk about personal qualities and how to compare people.
Two. Key phrases (key phrases):
What is the frequency of 1? How much is once in a while?
2. Junk food
3. Lots and lots
4. It is almost never rare.
Step 5 start ...
6. Try to do something. Try to do sth.
7. Take care of care
8. A little unhealthy.
9. once a day once a day
10. Twice a month
1 1. Good for ...
12. Occasionally
13. See a doctor/dentist.
14. Cold/fever
15. Abdominal pain.
16. Toothache
Sore throat.
18. Lie down and rest.
19. Drink hot tea with honey.
20. nervous
2 1. Listen ...
22. tired
23. Stay healthy.
24. At the moment; at present
25. Watch TV. Watch TV
26. Play basketball
27. Look after her sister.
28. Visit my friends. Visit my friends
29. Relax at home.
30. Sports camping
3 1. Interesting thing
32. Go hiking/camping/fishing/shopping/sightseeing
Go hiking/camping/fishing/shopping/sightseeing
33. Leave
34. go back to school
Stay for a week.
36. Go for a ride by bike
37. Take a walk
38. Video rental by video rental.
39. Sleep more and sleep more.
40. consider
4 1. Take the subway/bus/boat/plane
By subway/bus/boat/plane
42. Arrive
43. Go by bus/plane/boat.
44. Train/subway/bus station
45. Travel by bus.
46. Ride a bike
47. Bus stop
48. Walk on foot
49. Ask for leave ...
50. school bus school shuttle bus
5 1. Early bus, early bus
Different from ... ...
53. Half past six
In North America is in North America.
55. Fast breakfast
56. Need to do need to do ...
57. exceed
58. Play football
59. Baseball game Baseball game
60. School team
6 1. Come and come …
62. The day after tomorrow
Be good at ...
64. Two years ago.
65. extroversion and extroversion
66. All along,
67. In some ways, in some ways.
68. It looks the same.
69. Talk to everyone.
70. Make me laugh. Make me laugh
Key sentence patterns:
Unit 1:
1.- What do you usually do on weekends?
-I usually go to the movies.
2.- What does he sometimes do on weekends?
-He sometimes goes online.
3. How often do you exercise?
I exercise once a week.
How often does she eat vegetables?
She eats vegetables three times a day.
Most students go to the beach every year.
6. This has a great influence on my grades.
7. I have a good eating habit.
Unit 2:
1. What happened?
What's the matter?
Is there any trouble?
I don't feel well. I have a cold/fever/stomachache/sore throat.
/I have a headache.
Maybe you should see a doctor/dentist.
You should drink some hot tea with honey.
You shouldn't eat anything for 4.24 hours.
5. Don't be nervous. It will make you sick.
I am sorry to hear that you are not feeling well.
Unit 3
1.- What is she going to do on holiday?
-She's looking after her little sister.
-Sounds good/interesting.
2.- When are you going?
-I'm leaving on Monday.
3.- Where are they going?
-They're going to Tibet.
4.- Who is she going with?
-She's going with her parents.
5.- How long will he stay?
-He's staying for a week.
6.- What is the weather like there?
-I hope the weather will be fine.
He will go to Hong Kong in the first week of June.
8. Have a good time.
Unit 4:
1.- How do you get to school?
-I go to school by bus.
2.- How does he go to work?
-He usually walks to school.
3.- How long will it take?
-It will take about twenty minutes.
4.- How far is it from his home to school?
-It's three miles.
What do you think of the traffic in your town?
Unit 5:
1.- Can you come to my party on Wednesday?
-Sure, I'd love to. /Sorry, I have to go to the piano class.
2.- Can she go to the movies on Saturday?
-No, she can't. She must help her mother.
3.- Can you go to the concert on Monday?
-When?
-It's four o'clock on Friday afternoon.
4. Thank you very much for your invitation.
I will study for the exam tonight.
6. What's the date today?
Unit 6
1. Pedro is more interesting than Paul.
Tina is taller than Tara.
I love sports more than my best friend.
My hair is longer than hers.
Liu Ying is not as good as her sister.
6. In some ways, we look the same.
7. For me, good friends like to do the same things with me.
I am quieter than most children in my class, and so are my friends.
9. Who do you think should get the job, Ruth or Ross?
Please adopt the following suggestions. thank you