Question

How does a sound wave change according to the increasing or decreasing of its speed?

Answer 1

The speed of a sound wave refers to how fast it travels through a medium. When the speed of a sound wave changes, it can affect various properties of the wave. Here are some key changes that occur when the speed of a sound wave is altered:

1. Wavelength: The wavelength of a sound wave is the distance between two consecutive points of similar phase, such as two adjacent compressions or rarefactions. When the speed of sound changes, the wavelength also changes inversely. If the speed of sound increases, the wavelength becomes shorter, and if the speed decreases, the wavelength becomes longer.

2. Frequency: The frequency of a sound wave is the number of complete cycles it completes in a given time. The frequency remains constant for a sound wave as it travels through a homogeneous medium. However, when the speed of sound changes, the time required to complete a cycle also changes. Therefore, if the speed of sound increases, the frequency of the wave remains constant, but if the speed decreases, the frequency also decreases.

3. Pitch: The pitch of a sound is our perception of its frequency. When the speed of sound changes, it affects the frequency of the wave, resulting in a change in pitch. If the speed of sound increases, the frequency and pitch of the sound also increase, whereas if the speed decreases, the frequency and pitch decrease.

4. Amplitude: The amplitude of a sound wave represents the maximum displacement of particles in the medium from their equilibrium position. When the speed of sound changes, it does not directly affect the amplitude of the wave. However, changes in the medium's properties due to variations in the speed can indirectly affect the amplitude, such as through reflections, refractions, or interactions with obstacles.

It's important to note that changes in the speed of sound primarily occur when the wave passes from one medium to another, where the properties of the medium, such as density or elasticity, differ. In homogeneous media, where the properties remain constant, the speed of sound is typically constant as well.