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  • General

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  • 波波频率

    A person shaking a rope attached to a tree, illustrating wave frequency concepts.

    Imagine making transverse waves in a rope, like the person in the sketch above. You tie one end of the rope to a tree or other fixed point, and then you shake the other end of the rope up and down with your hand. You can move the rope up and down slowly or quickly. How quickly you move the rope determines the frequency of the waves.
    ::想象一下在绳子上制造横跨波, 像上面的草图中的人那样。 你将绳子的一端绑在树上或其他固定点上, 然后用手摇动绳子的另一端。 你可以慢慢地或迅速地移动绳子。 绳子的移动速度决定波子的频率 。

    What Is Wave Frequency?
    ::"浪潮频率"是什么?

    The number of waves that pass a fixed point in a given amount of time is wave frequency . Wave frequency can be measured by counting the number of crests (high points) of waves that pass the fixed point in 1 second or some other time period. The higher the number is, the greater the frequency of the waves. The SI unit for wave frequency is the hertz (Hz) , where 1 hertz equals 1 wave passing a fixed point in 1 second. The Figure shows high-frequency and low-frequency transverse waves. 
    ::在一定时间内通过固定点的波的波数是波频率。波的频率可以通过在1秒或某个其他时间段通过固定点的波数(高点)来计算。波数越高,波的频率就越大。波频率的SI单位是赫兹(赫兹),1赫兹等于1波,1秒通过固定点。图显示高频和低频跨波。

    Comparison of high-frequency and low-frequency transverse waves showing varying wavelength and crest spacing.

    Q: The of a wave is the between corresponding points on adjacent waves. For example, it is the distance between two adjacent crests in the transverse waves in the diagram. Infer how wave frequency is related to wavelength.
    ::Q:波的值是相邻波的对应点之间的值。例如,它是图中横向波的两个相邻的顶峰之间的距离。推断波的频率与波长的关系。

    A: Waves with a higher frequency have crests that are closer together, so higher frequency waves have shorter wavelengths.
    ::A:高频波的顶峰更近,因此高频波的波长更短。

    Wave Frequency and Energy
    ::波浪频率和能源

    The frequency of a wave is the same as the frequency of the vibrations that caused the wave. For example, to generate a higher-frequency wave in a rope, you must move the rope up and down more quickly. This takes more , so a higher-frequency wave has more energy than a lower-frequency wave with the same amplitude . You can see examples of different frequencies in the Figure (Amplitude is the distance that particles of the medium move when the energy of a wave passes through them.)
    ::海浪的频率与引发波浪的振动频率相同。例如,为了在绳索中产生高频波,必须更快地将绳索上下移动。这需要更多时间,因此高频波的能量比同一振幅的低频波的能量要多。您可以看到图中不同频率的例子(调幅是当波的能量通过时介质粒子移动的距离)。

    Comparison of wave frequencies showing lower frequency (lower energy) and higher frequency (higher energy).

     

     

    Summary
    ::摘要

    • Wave frequency is the number of waves that pass a fixed point in a given amount of time.
      ::波频率是指在一定时间内通过固定点的波数。
    • The SI unit for wave frequency is the hertz (Hz), where 1 hertz equals 1 wave passing a fixed point in 1 second.
      ::海浪频率的SI单元是赫兹(Hz),其中1赫兹等于1波,在1秒内通过固定点。
    • A higher-frequency wave has more energy than a lower-frequency wave with the same amplitude.
      ::高频波的能量大于同一振幅的低频波的能量。

    Review
    ::回顾

    1. What is wave frequency?
      ::什么是波频率?
    2. What is the SI unit for wave frequency?
      ::海浪频率的SI单位是什么?
    3. Assume that 10 waves pass a fixed point in 5 seconds. What is the frequency of the waves in hertz?
      ::假设10波在5秒内通过固定点。 赫兹波的频率是多少?
    4. Relate wave frequency to the energy of waves.
      ::将波的频率与波的能量相对应