Longitudinal wave A wave motion in which the individual particles vibrate back and forth along(parallel to fi])the direction of the wave's travel is called a longitudinal or compressible(压缩)wave. For examples: Sound waves as shown in Figure condensation rarefaction Tip piston 振动 波动
Longitudinal Wave: A wave motion in which the individual particles vibrate back and forth along (parallel to：平行) the direction of the wave’s travel is called a longitudinal or compressible(压缩) wave. For examples: Sound waves as shown in Figure: condensation rarefaction稀 piston 振动 波动
Sound wave Figure 15-8 A drawing of a longitudinal sound wave. The dark regions represent compressions (high density), the lighter regions represent rarefactions dlow den sity )
Sound wave
The general waves are treated as the mixed waves as a combination of longitudinal and transverse wave. For example: ()Water wave. (2)Earthquake waves
The general waves are treated as the mixed waves as a combination of longitudinal and transverse wave. For example: (1)Water wave. (2)Earthquake waves
Other classification. IOne-dimensional waves: a wave in a string (2)Two-dimensional waves: water wave (Three-dimensional waves: the flash of light 高能激光
Other classification: (1)One-dimensional waves: a wave in a string; (2)Two-dimensional waves: water wave; (3)Three-dimensional waves: the flash of light
3. Velocity wavelength and frequency Take a sinusoidal(正弦波) wave in a string as example. The shape of wave Crest: 波峰(peak)y 峰 Trough:波谷(valy) X 波速:扰动一 秒钟传播的距离为 波速。 One second 波长A: the distance from crest to adjacent(毗连的) crest or trough to adjacent trough
3.Velocity wavelength and frequency Take a sinusoidal(正弦波) wave in a string as example. Crest:波峰(peak) Trough:波谷(valley) 波速 ：扰动一 秒钟传播的距离为 波速。 V 波长 ：the distance from crest to adjacent(毗连的） crest or trough to adjacent trough. x y o The shape of wave V One second 峰 谷