Summary of high school physics compulsory elective knowledge points, attention, it is about genera

Take a look at three or two and solve it.

If you have a clear understanding of the knowledge points in physics and a clear combing of the content of the knowledge points, it will be easier to learn

Chapter 1 Description of the Movement

1. Three concepts.

Particle: A point used to replace all the mass of an object.

Conditions for the appearance of particles: the size and shape of the object have no or negligible influence on the problem under study.

Coordinate system: quantitatively describes the position of an object and the change in its position.

2. Describe the physical quantities of motion.

3. Use images to describe the movement of objects.

X-T image.

Significance: Indicates the law of displacement over time.

Application: Determine the nature of movement; determine the direction of movement; Compare the speed of movement; Determine the correspondence between displacement and time.

V-T image.

Significance: Indicates the law of velocity over time.

Application: Determine the speed at a certain moment; judging the nature of the movement; determine the direction of movement; Determine the magnitude of acceleration (using slope).

4. Experiment: Use a dot timer to measure the speed.

A dot timer is an instrument that uses alternating current.

Chapter 2 Research on Linear Motion at Uniform Speed.

1. Experiment: **The law of the change of trolley speed with time.

2. Uniform variable speed linear motion.

Velocity—a temporal image.

Displacement—Time image.

3. Special case: free fall movement.

Chapter 3 Interaction – Force.

1. Awareness of force.

2. Three common forces.

3. Balance of common point forces.

Movement characteristics: maintain a state of stationary or uniform linear motion.

Force characteristics: net force f=0

Processing methods: synthesis method, decomposition method, orthogonal decomposition method.

4. Synthesis and decomposition of force.

Rules to be followed: Parallelogram rule or triangle rule.

Experiment: The law of the synthesis of two forces at angles to each other.

Resultant force and component force: equivalent substitution relation.

Range of resultant force: |f1-f2|≤f≤f1+f2

5. Newton's third law: The force and reaction force between two objects are always equal in magnitude and opposite in direction, acting on the same straight line.

Action and reaction forces.

Concept: A pair of forces that interact with each other.

Characteristics: always interdependent, coexisting, of the same nature.

The difference between a pair of equilibrium forces: object & effect.

Chapter 4 The Relationship between Motion and Force.

1. Newton's first law.

Galileo's ideal experiment.

Contents: All objects remain in a state of uniform linear motion or stationary unless an external force acting on them forces it to change its head and destroy this state.

Understanding: Describes an ideal state, not an experimental law.

Force is the reason why an object changes its state of motion.

Inertia: All objects have inertia in all circumstances, and mass is the only measure of the magnitude of inertia.

2. Newton's second law.

3. Mechanical unit system.

The unit system consists of the base unit and the derived unit.

International System of Units Application of the system of units.

4. Application of Newton's laws of motion.

There are two basic types of problems: the known motion situation and the force situation.

If you know the force situation, you can find the motion situation.

Overweight and weightlessness:

Overweight – acceleration a upward, fn>g

Weightlessness – acceleration a downward, fn complete weightlessness – a = g, fn = 0