On The Nature of Transverse Waves

[JordanH]

hello all,
i am new to this forum and to physics itself. I am a high school student who has studied physics for about two weeks. Regardless of this, while studying a question arose. it is this;

according to the theory of superposition, two waves moving in opposite directions, one positive and one negative, will interact destructively causing the wave to level to the average position between these two waves. In the event that the waves are of the same magnitude, one being A(1)=X the other being A(2)=-X, the wave will level to zero, or, the particles' mean position. Let us take for example particle P which resides at the exact point of which the two waves would meet. when the positive wave hits P the particle will have a force applied to it, causing it to move in the positive direction (towards the peak of the positive wave). When we introduce the second, Negative, wave into this equation, particle P is having force applied from both sides; positive and negative. It is my understanding that the action that would result from this would be much like that of an object at rest; forces are balanced therefore it does not accelerate in any direction.
Superposition seems to support this when it states that the wave would level to zero. In effect, the particles stop moving.

It is my understanding that the way a wave commutes energy is through the vibration and movement of the particles of the medium.

Superposition also states that after the addition of the Amplitudes of the waves, the waves both continue, unaffected, at their original amplitude, in their original direction.

How can this be if the particles have ceased to move and therefore have ceased to transmit the energy?

I know that superposition does occur in this form because it can be observed in numerous tests. what i don't understand is how the aforementioned instance can occur.

any enlightenment would be very much appreciated.


thanks,

Jordan

 

[AndyW]

Hello Jordan,

First of all, welcome to the forum and to the world of physics! It's great to see your curiosity and interest in the subject.

To answer your question, let's start by clarifying the concept of superposition. Superposition is the principle that states that when two waves meet, their amplitudes (or heights) are added together to produce a resultant wave. This resultant wave is the sum of the two waves and may have a different amplitude, frequency, and direction than the individual waves.

In the example you provided, the two waves are moving in opposite directions and have the same amplitude but opposite signs. When they meet, their amplitudes will cancel out and the resultant wave will have an amplitude of zero. This means that at the point where the two waves meet, there will be no net displacement of the particles in the medium. However, this does not mean that the particles have stopped moving altogether.

Remember, a wave is a disturbance that travels through a medium, and the particles of the medium are not permanently displaced from their equilibrium position. They simply oscillate back and forth as the wave passes through them. In the case of destructive interference, the particles may not have a net displacement, but they are still oscillating and transmitting energy.

So, to answer your question, the particles have not ceased to move and transmit energy. They are still oscillating, but the net displacement at the point of destructive interference is zero.

I hope this helps clarify the concept of superposition for you. Keep exploring and asking questions, and you will continue to deepen your understanding of physics. Best of luck with your studies!

 

[sir-pinski]

Hi Jordan,

Welcome to the forum and to the world of physics! Your question is an excellent one and it shows that you are thinking critically about the concepts you are learning. Let me try to provide some clarification on the nature of transverse waves and how superposition works in this case.

First, let's define transverse waves. These are waves where the particles of the medium move perpendicular to the direction of the wave. Examples of transverse waves include electromagnetic waves (such as light) and water waves. In these waves, the particles do not move in the direction of the wave, but rather oscillate up and down or side to side.

Now, let's consider what happens when two transverse waves with equal amplitudes and opposite directions meet. As you correctly stated, the particles at the point of intersection will experience forces in both directions, causing them to remain at rest. However, this does not mean that the particles have stopped moving altogether. They are still vibrating or oscillating in their original direction, but the forces from the two waves cancel each other out, resulting in no net movement.

Think of it this way: imagine two people pushing on a door from opposite sides with equal force. The door will not open or close, but it is still being pushed and experiencing forces from both directions.

As for the energy transfer, it is important to note that in transverse waves, the particles of the medium do not actually travel with the wave. They only vibrate in place, while the wave itself travels through the medium. So even though the particles may not be moving in a certain region, the wave is still carrying energy through that region.

I hope this helps to clarify the concept of transverse waves and superposition. Keep asking questions and exploring the fascinating world of physics! Best of luck in your studies.