The Student Room Group

Standing Waves (AS Phys)

Q. Explain how standing wave is produced.

My answer:

When a wave is generated from one side of a medium, it travels without transferring energy to the other end of the same medium. This makes it a non-progressive wave, because they store energy and not transfer energy. It has nodes and antinodes. These are fixed points on the wave.

Nodes are points with no oscillations of particles or they are points where waves interfere destructively. Whereas, Antinodes are points on the wave, with maximum amplitude and oscillations of particles. Each point between two nodes, has different fixed amplitude to its neighbour.

When it reaches the other end of the medium, it gets reflected and inverted. Crest becomes the trough of the reflected wave.
The two waves (incident wave and reflected wave) superimpose or interfere constructively.


Can someone tell me if it's right?
(edited 2 years ago)
Original post by Aleksander Krol
Q. Explain how standing wave is produced.

My answer:

When a wave is generated from one side of a medium, it travels without transferring energy to the other end of the same medium. This makes it a non-progressive wave, because they store energy and not transfer energy. It has nodes and antinodes. These are fixed points on the wave.

Nodes are points with no oscillations of particles or they are points where waves interfere destructively. Whereas, Antinodes are points on the wave, with maximum amplitude and oscillations of particles. Each point between two nodes, has different fixed amplitude to its neighbour.

When it reaches the other end of the medium, it gets reflected and inverted. Crest becomes the trough of the reflected wave.
The two waves (incident wave and reflected wave) superimpose or interfere constructively.


Can someone tell me if it's right?

How many points is it for?

Main point IMO is that you have progressive waves of the same frequency travelling in different directions through the same medium and interfering with each other.

I'm a bit confused by your 1st paragraph - you could probably delete it and start off talking about constructive and destructive interference producing antinodes and nodes at fixed positions.
Original post by Aleksander Krol
Q. Explain how standing wave is produced.

My answer:

When a wave is generated from one side of a medium, it travels without transferring energy to the other end of the same medium. This makes it a non-progressive wave, because they store energy and not transfer energy. It has nodes and antinodes. These are fixed points on the wave.

Nodes are points with no oscillations of particles or they are points where waves interfere destructively. Whereas, Antinodes are points on the wave, with maximum amplitude and oscillations of particles. Each point between two nodes, has different fixed amplitude to its neighbour.

When it reaches the other end of the medium, it gets reflected and inverted. Crest becomes the trough of the reflected wave.
The two waves (incident wave and reflected wave) superimpose or interfere constructively.


Can someone tell me if it's right?

I agree with Joinedup’s comment on your answer and a slight disagreement with the suggested answer.
Joinedup suggested “… progressive waves of the same frequency travelling in different directions through the same medium and interfering with each other.”

In the formation of standing waves, the waves need to travel in opposite directions instead of in different directions.

Below are some suggested points to consider:
The waves must be of similar type with the same amplitude, frequency, wavelength and speed.
The two waves travel in opposite directions OR the incident wave and the reflected wave.
The waves superpose.
In some positions, the waves are always exactly out of phase, so they interfere destructively forming nodes. The amplitude at nodes is zero.
The antinodes are midway between each pair of nodes where the waves are in phase and interfere constructively to produce maximum amplitude.

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