Summary of mathematics, English, and physics knowledge in the first half of the second semester of j

Mechanics 1Newton's First Law.

2.Newton's first law is also known as the law of inertia.

3.Inertia. 4.The conditions for the balance of the two forces.

5.Frictional force.

6.Pressure. 7.Pressure.

8.Piezometer.

9.Formula p= gh

10.Communicators.

11.Atmospheric pressure.

The atmospheric pressure of a millimeter mercury column is called a standard atmospheric pressure.

13.Atmospheric pressure.

Electricity is the main one. 1.Triboelectric generation.

2.The same charge repells each other, and the different charges attract each other.

3.Electricity. 4.Electric charge.

5.The directional movement of the charge forms an electric current. The direction in which the positive charge moves is defined as the direction of the current.

6.Conductors and insulators.

7.Power supplies, electrical appliances, switches. Circuit. Access; Open; Short circuit. Circuit diagram. Series circuits. Parallel circuits.

8.The current intensity is equal to the amount of electricity that passes through the conductor cross-section in 1 second.

9.The instrument that measures the current is called an ammeter.

10.Ammeter use.

11.The voltage causes an electric current to form in the circuit.

12.Measure the voltmeter.

13.Voltage.

14.Resistance.

Only the first two lessons Chapter 1 Acoustic Phenomena Sound is produced by the vibration of an object: the propagation of sound requires a substance, and physics calls this substance a medium, and the magnitude of the speed of sound is related to the medium, and also to the temperature of the medium.

Upstairs buddy, you're so good.

Middle School Mathematics: 1Rational number 2

The addition and subtraction of the whole formula (+ the city of the whole formula is in the factorization and fraction of the formula)3Unary Equation 4Preliminary understanding of graphics 5

Intersecting lines and parallel lines 6Planar Cartesian coordinate system 7Triangle 8

Binary Linear Equation 9Inequalities and inequalities group 10Collection, collation and description of data11

Congruent triangle 12Axisymmetric 13Real number 14

One function 15Inverse proportional function 16Pythagorean theorem 17

Quadrilateral 18Analysis of the data19Quadratic radical 20

Unary quadratic equation 21Spin 22Round 23

Probability 24Quadratic functions 25Similar 26

Acute trigonometry 27Projection & View.

Because they are all comprehensive investigations, the combination of knowledge points is more important] (I'm tired to death, the other two won't be played first,)

Chapter 1: Acoustic Phenomena The Production and Propagation of Sound 1, Sound is produced by the vibration of objects 2, the substance that transmits sound is called a medium, and the vacuum cannot transmit sound 3, Sound travels in the form of sound waves 4, 15 The speed of sound in the air is 340m s How do we hear sound 1, The human ear hears sound: Sound causes the eardrum to vibrate, and it is transmitted to the auditory nerve through the ossicles and other tissues, and the auditory nerve transmits the signal to the brain 2, Bone conduction:

Sound can also be transmitted to the auditory nerve through the jaw and skull, causing hearing 3, binaural effect: the time, intensity and other characteristics of sound transmitted from the sound source to the ears are different Characteristics of sound 1, the relationship between tone and frequency: the greater the frequency, the higher the pitch 2, the relationship between loudness and amplitude:

The greater the amplitude, the greater the loudness 3, timbre: different vocal emitters, different timbre 4, human auditory frequency range: 20hz 20000hz 5, ultrasound:

Sound above 20000hz 6, Infrasound: sound below 20Hz Harm and control of voice 1, voice; The sound emitted when the sound emitter vibrates irregularly 2, the level of sound intensity, unit: decibels, symbol db 3, three ways to control noise:

Prevent the generation of voice, block the transmission of noise, and prevent the voice from entering the human ear The use of sound 1, sound and information: the use of sonar systems to explore the depth of the ocean, which works according to the principle of echolocation 2, sound and energy: sound can transmit energy.

Example: Ultrasonic Cleaning Precision Instrument Chapter 2 Light Transmission Light Propagation: 1. Light source:

Natural light source, artificial light source 2, light propagation in the same uniform medium along a straight line 3, speed of light: the speed of light in a vacuum is the fastest speed in the universe c = 3 10 to the eighth power of the reflection of light 1, the reflection of light 2, the law of reflection of light: in the reflection phenomenon, the three lines are coplanar, the normal is centered, and the two angles are equal; In the phenomenon of reflection, the optical path is reversible 3. Classification:

Specular reflection, diffuse reflection plane mirror imaging 1, plane mirror imaging characteristics: the size of the image and the object are equal; The coupling of the corresponding point of the image and the object is perpendicular to the mirror; The distance between the image and the object is equal to the mirror; Virtual image 2, spherical mirror: convex mirror has a divergent effect on light, concave mirror has a converging effect on light Refraction of light 1, refraction phenomenon of light 2, law of refraction of light:

trilinear coplanar; fold and into the two sides of the law of separation; The angle of refraction is less than the angle of incidence (light-air) The angle in the air is greater than the angle of any medium; Light is perpendicular to another medium, and the direction of propagation does not change; The angle of incidence increases, the angle of refraction increases 3, the reversibility of light 4, and the interpretation of light phenomena in life.