How to calculate the period of a wave

How to calculate the period of a wave

Many scientific disciplines incorporate the concepts of wave frequencies and periods. Physicists, engineers and astronomers, study and work with the energy of the waves. Examples of wave energy are light waves of a distant galaxy, radio waves received by a cell phone and the sound waves of an orchestra. Regardless of the source of the wave, the relationship between waveform frequency and the period is the same. A wave period is the time in seconds between two wave peaks and is inversely proportional to frequency.

Steps to follow:

If you want to know the period of a wave, start by counting the number of times the wave reaches its peak in a certain period of time. Use an oscilloscope to see the shape of the wave.

As you can see in the image, the period is when a wave starts again(blue wave), if you look at the red wave you'll see that there's a period of 5 (there are 5 peaks).


Now, divide the number of waves by the amount of time in seconds. This number will give us the frequency of the wave. For example, suppose that 21 waves are produced in 3 seconds. Its frequency equals 21 divided by 3, which is 7 Hz. Frequency units are Hertz.

Another example:

  • The image in the top square has a total of 5 waves in 5 seconds, so the frequency is equivalent to 5 divided by 5, which equals 1 Hertz.
  • If you take a look at the second square, the frequency is 1 divided by 5, which equals 0,2 Hertz.

Calculate the opposite of the frequency to get the period of the wave. For example, one divided by 7 Hertz equals a period of approximately 0.14 seconds.

In the example images:

  • The period in the top image is 1 divided by 1 Hz, which is 1 second.
  • The period of the bottom image is 1 divided by 0,33 Hz, which is 3 seconds.

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