Lesson 3, Lesson 4 sections A-C
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A standing wave pattern is a vibrational pattern created within a medium when the vibrational frequency of the source causes reflected waves from one end of the medium tointerfere with incident waves from the source.
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- Mechanical wave is a disturbance created by a vibrating object
- Energy is moved from particle to particle
- Waves transport energy not matter
- "As a wave is observed traveling through a medium, a crest is seen moving along from particle to particle. This crest is followed by a trough that is in turn followed by the next crest. In fact, one would observe a distinct wave pattern (in the form of a sine wave) traveling through the medium. This sine wave pattern continues to move in uninterrupted fashion until it encounters another wave along the medium or until it encounters a boundary with another medium. This type of wave pattern that is seen traveling through a medium is sometimes referred to as a traveling wave." (from textbook)
- Occur when wave is not in confined space
- Example is an Ocean wave
- When a wave pattern (vibrations) stay the same there is negative displacement
- Nodes- don’t move
- Anti-nodes- move
- Standing waves have harmonic frequencies
- Use fixed end reflection to keep moving
- Turn upwards energy in to downwards and vice versa
- Destructive interference in a wave causes the individual waves to keep their direction but cut the height
- Constructive interference makes the waves shoot up
- Timing has to be perfect in order for constructive of destructive interference
- If timing is off anti-nodes and nodes will be off
- Nodes- 0 displacement. Middle of a wave
- Anti-nodes- displacement. Peak of a wave
- Standing waves always have an alternating pattern of Nodes and Anti-nodes