16.5波幅幅幅幅
Section outline
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On a windy day, moving air particles strike these flags and transfer their of motion to particles of fabric. The energy travels through the fabric in waves. You can see the waves rippling through the brightly colored cloth. The windier the day is, the more vigorously the flags wave.
::在风吹日,移动的空气颗粒击中这些旗帜,将其运动转移到织物的颗粒上。能量在结构中波浪穿行。你可以看到波浪在光亮的彩色布料中波动。日风越大,旗帜波浪越大。What’s the Matter?
::有何贵干?Waves that travel through matter—such as the fabric of a flag—are called mechanical waves. The matter they travel through is called the medium . When the energy of a wave passes through the medium, particles of the medium move. The more energy the wave has, the farther the particles of the medium move. The the particles move is measured by the wave’s amplitude .
::穿过物质的波浪——例如旗帜的构造——被称为机械波。它们穿过的波波被称为介质。当波的能量通过介质时,介质移动的粒子。波的能量越大,介质移动的粒子就越远。粒子移动用波的振幅来测量。What Is Wave Amplitude?
::波浪幅是什么?Wave amplitude is the maximum distance the particles of the medium move from their resting positions when a wave passes through. The resting position of a particle of the medium is where the particle would be in the absence of a wave. The Figure show the amplitudes of two different types of waves: transverse and longitudinal waves.
::波的振幅是当波经过时,介质的粒子从其静坐位置移动的最大距离。介质的粒子的静坐位置是粒子在没有波的情况下的位置。图显示两种不同类型的波的振幅:横向波和纵向波。-
In a
, particles of the medium move up and down at right angles to the direction of the wave. Wave amplitude of a transverse wave is the difference in height between the crest and the resting position. The crest is the highest point particles of the medium reach. The higher the crests are, the greater the amplitude of the wave.
::在 a 中, 介质的粒子会从右角度向上向下移动到波浪的方向。 横波的波幅是峰顶和休息位置之间的高度差异。 顶峰是中位角的最高点粒子。 顶峰越高, 浪的振幅就越大。 -
In a
, particles of the medium move back and forth in the same direction as the wave. Wave amplitude of a longitudinal wave is the maximum distance particles move from their resting positions when the medium is compressed by the wave. It isn’t as easy to visualize in a longitudinal wave compared to a transverse wave, but the closer together the particles are in an area of compression, the greater the amplitude of the wave.
::介质的粒子向上向后向向向移动。 纵向波浪的波幅是当介质被波压缩时从静坐位置移动的最大距离粒子。 与反向波相比,在纵向波中视觉化并不容易,但粒子越靠近压缩区域,波的振幅越大。
Q: What do you think determines a wave’s amplitude?
::问题:你认为波浪的振幅由什么决定?A: Wave amplitude is determined by the energy of the disturbance that causes the wave.
::A:波的振幅是由引发波的扰动的能量决定的。Energy and Amplitude
::能源和振幅A wave caused by a disturbance with more energy has greater amplitude. Imagine dropping a small pebble into a pond of still water. Tiny ripples will move out from the disturbance in concentric circles. The ripples are low-amplitude waves with very little energy. Now imagine throwing a big boulder into the pond. Very large waves will be generated by the disturbance. These waves are high-amplitude waves and have a great deal of energy.
::由能量较多的扰动引发的波浪具有更大的振幅。 想象一下将小块石块投入静水池。 小波纹会从同心圆的扰动中移出。 波纹是低温波, 能量很小。 现在想象一下向池塘投掷大块巨石。 大波会因扰动而产生。 这些波纹是高压波, 具有巨大的能量 。Summary
::摘要-
Wave amplitude is the maximum distance the particles of the medium move from their resting positions when a wave passes through.
::波的振幅是当波经过时,介质粒子从静坐位置移动的最大距离。 -
Wave amplitude of a transverse wave is the difference in height between a crest and the resting position.
::横波波的波幅是顶峰和休息姿势之间的高度差异。 -
Wave amplitude of a longitudinal wave is the maximum distance particles move from their resting positions when the medium is compressed by the wave. The closer the particles of the medium are in areas of compression, the higher the amplitude.
::纵向波浪的波幅是,当介质被波压缩时,最大距离粒子从静止位置移动。介质的粒子越靠近压缩区域,振幅越高。 -
Wave amplitude is determined by the energy of the disturbance that causes the wave. A wave caused by a disturbance with more energy has greater amplitude.
::波的振幅由引发波浪的扰动的能量决定。 以更多能量引发的扰动所产生的波浪的振幅更大。
Review
::回顾-
Define wave amplitude.
::定义波的振幅 。 -
What is the amplitude of the transverse wave modeled in the
Figure
if the height of a crest is 3 cm above the resting position of the medium?
::如果一个山峰的高度超过介质休息位置的3厘米,图中模型的横向波的振幅是什么?
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Which of these two longitudinal waves in the
Figure
has greater amplitude?
::图中这两个纵向波的哪个的振幅更大?
Note: The darker the color, the closer the particles of the medium are together.
::注:颜色越暗,介质粒子越近,介质的粒子就越近。-
Relate wave amplitude to wave energy.
::与波浪能量相对应的波浪振幅
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In a
, particles of the medium move up and down at right angles to the direction of the wave. Wave amplitude of a transverse wave is the difference in height between the crest and the resting position. The crest is the highest point particles of the medium reach. The higher the crests are, the greater the amplitude of the wave.