How to look at the direction of motion of the particle and the direction of propagation of the wave

There are three ways to judge this. Since I can't transfer the map, I'll talk about the easiest method - the up-and-down wave method.

For example, a wave travels from left to right. Then from its up and down fluctuations, you can judge that the upward wave is the upper wave, and the downward wave is the lower wave. Then remember one sentence. "The upper wave is down, and the lower wave is up"

If the direction changes, the lower wave just now becomes the upper wave, and the situation is different!

Then judging the direction of the wave propagation can also be extrapolated backwards using this method!

If you don't understand, just call me. I'll show you!

If the wave is to the right, you see whether the left side of the particle is above or below the particle, that is the direction of the particle, when the direction of the particle is known, look at the left and right, and the same direction as the particle is the direction of the wave.

The easiest way: Look from left to right to set the rules for going uphill and downhill.

The particle moves uphill upward, the particle moves downhill downhill, and the wave propagation direction is to the right.

The particle moves uphill and downhill, and the particle moves downhill and upward, and the wave propagation direction is to the left.

In both cases.

Uphill, downhill, to the right.

Uphill downhill, downhill, to the left.

The same is true for judging particles based on the direction of the wave.

The direction of movement of the particle and the direction of propagation of the wave are always on the same side of the image, it is impossible to draw a vibrating image on the inside of the parabola and one on the outside.

When I was in high school, our teacher taught us one"Reverse tracing":

In the image of a wave, the direction of movement of the particle is the direction in which it was traced in the direction of propagation, and in the process of backtracking, the direction of movement of the particle is the direction in which it was traced.

For example, if you swing a soft rope vertically up and down, the rope will move horizontally!

**The particle vibration direction of the transverse wave in the wave is perpendicular to the direction of motion of the wave.

The deformation caused by the propagation of the ** wave in the rock and soil leaving the epicenter is small, which can be regarded as elastic, and the observation instrument records the elastic ** wave. There are two types of elastic ground key shock waves: body waves and surface waves, where body waves are divided into longitudinal waves (P waves) and transverse waves (S waves).

Surface waves are further divided into Rayleigh waves (R-waves) and Ralph waves (L-waves).

The difference between the velocity of a transverse wave and a longitudinal wave

1. Different meanings: transverse wave refers to the wave in which the vibration direction of the particle in the medium is perpendicular to the propagation direction of the wave, while the longitudinal wave refers to the wave in which the vibration direction of the particle in the medium and the propagation direction of the wave are parallel to each other.

2. Different characteristics: the transverse wave is also known as the "$" wave, which belongs to the cross-cutting wave, and the second one reaches the epicenter, which can make the ground shake back and forth, left and right, and the destructive is relatively strong; The longitudinal wave, also known as the "p" wave, is a propulsion wave, which reaches the epicenter first, and it can make the ground shake up and down, and the damage is weaker than the transverse wave.

3. The longitudinal waves of the epicenter generated by the large ** source and the shear longitudinal wave generated by the fault plate are caused by the discharge of gas from the earth's interior. Before the gas breaks through the earth's crust, it mainly exhibits the characteristics of the longitudinal wave of the vibrator, and after the gas breaks through the crust, it mainly exhibits the characteristics of shear longitudinal wave.

Answer: The particle of the wave is moving up and down, and the mass locust type point close to the wave source vibrates up and down first, causing the particle vibration that is far away from the wave source to guess the lead source, and the vibration of the distant particle point causes the vibration of the particle point to be farther away, so that the vibration propagates from near and far, so the wave propagates not the particle, the wave propagates the vibration, propagates the pure vibration form, and propagates the energy.

In the case of a particle, look at the position of the previous point, if the previous position is below this particle, then the particle is down, and vice versa.

And the first position I'm talking about isn't the left side of the axis. It depends on whether the wave is from left to right, or right to left.

If you go from left to right, the previous position refers to the left, and vice versa, the right.

Creeping wave method: If the tip of the pen moves in the opposite direction of the wave propagation direction (following the trajectory of the wave), then the direction of the nib movement (perpendicular to the direction of wave propagation) is the same as the vibration direction of the particle.

Look at where the closest intersection point is from the x-axis, and the horizontal direction in which the particle points to that intersection point is the direction of wave propagation.

1. "Up and down.""Law.

Looking in the direction of the wave's propagation, the uphill point moves downwards and the downhill point moves upward. That is, "uphill downhill, downhill uphill.""。Reverse thinking of this approach.

2. Reverse description method.

Use a pencil to trace the waveform curve, the direction of the particle is upward, and the pen tip moves upwards along the wave curve; The direction of the particle is downward, and the tip of the pen follows downward. The direction of the wave is the opposite direction of the pen's movement.

3. Same side method.

The wave curve divides the coordinate plane into two half-planes, and the direction of the wave propagation and the direction of vibration of the particle are on the same side of the wave.

Lack of image combination description, you can make more pictures to combine the method is easy to come up with.

Summary. A particle is a point with mass that ignores the size and shape of an object. It is a scientific abstraction, an idealized physical model, an approximation of an actual object by grasping the main factors and ignoring the secondary factors when studying the motion of an object.

Characteristics of a particle: (1) It has no size or shape (2) It has the full mass of an object (3) It is an idealized model, and there are no three situations in which an object can be regarded as a particle: (1) The size of a moving object is negligible compared to the distance between it and another object under study, and the object can be regarded as a particle.

2) For a translational object, since the motion of each point on the object is the same, the motion of any point on the object can be selected to represent the motion of the object, so the translational object can be regarded as a particle when studying its motion properties. (3) When there is rotation, but it is negligible compared to translation, the object can also be regarded as a particle. For example, when the car is running, although the wheels rotate, we are concerned about the speed of the overall movement of the vehicle, so the car can be regarded as a particle.

The nature of motion of the particles other than the wave source is.

A particle is a point with mass that ignores the size and shape of an object. It is a scientific abstraction, an idealized physical model, an approximation of an actual object by grasping the main factors and ignoring the secondary factors when studying the motion of an object. Characteristics of the Particle Trigger:

1) It has no size or shape (2) It has the full mass of an object (3) It is an idealized model that does not exist in real life There are three situations in which an object can be regarded as a particle: (1) The size of a moving object is negligible compared to the distance between it and another object under study, and the object can be regarded as a particle. (2) For a translational object, since the motion of each cover point on the object is the same, the motion of any point on the object can be selected to represent the motion of the object, so the translational object can be regarded as a particle when studying its motion nature.

(3) When there is rotation, but it is negligible compared to translation, the object can also be regarded as a particle. For example, when the car is running, although the wheels rotate, we are concerned about the speed of the overall movement of the vehicle, so the car can see things and take them into points.

Understanding of particles: Particles are physical models established to study the movement of objects, and are abstractions of the science of actual objects, and there is no lack of particles in reality Whether an object can be regarded as a particle is determined by the nature of the problem under study The same object can be regarded as a particle in some cases, and the hole cannot be regarded as a particle in other cases For example, when studying the time when a train crosses the bridge, you cannot regard the train as a particle, but when studying the time taken by the train from Beijing to Shanghai, you can see the train as a particle

It is correct to say that in the process of transverse wave propagation, the direction of vibration of the particle and the direction of propagation of the wave are perpendicular to each other. This is derived according to the definition of transverse waves.

Definition of transverse wave: The vibration direction of the particle is perpendicular to the propagation direction of the wave, and such a wave is called "transverse code search wave".

Transverse waves are characterized by the fact that the direction of vibration of the particle and the direction of propagation of the wave are perpendicular to each other.

Waves are divided into transverse waves according to the relationship between the propagation direction of the wave and the vibration direction of the medium particle: transverse wave and longitudinal wave The wave in which the propagation direction of the wave and the vibration direction of the medium particle are perpendicular to each other is called the transverse wave, and the wave in which the propagation direction of the wave is in the same straight line as the vibration direction of the medium particle is called the longitudinal wave

So the answer is: horizontal; Longitudinal