Riding the Sine Wave…
A sine wave is a repetitive change or motion which, when plotted as a graph, has the same shape as the sine function.
For example, on the right is a weight suspended by a spring. As it bounces up and down, its motion, when graphed over time, is a sine wave. In reality, friction and air resistance would cause the bouncing to slow down and eventually stop, but for illustration purposes we ignore that here.
Sound waves are very quick changes in air pressure which your ear interprets as sounds. For very pure single tones, a plot of air pressure against time would show them to be sine waves. For audio tones like this, pressure is cycling hundreds or thousands of times per second.
The height of a sine (or other) wave is called the “amplitude”. Another way to think of this is that it represents how much the sound increases (or decreases) in volume.
When you are at the beach you will notice that the waves come in almost regular intervals. The gap between the tops of the waves is called the “period” and this is the same if you take the distance between any two identical points on the wave:
In Mathematics, we study functions like the Sine curve, as it opens up so many practical applications to engineering and science, as well as music and hydrology and …. – you get the picture?
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