Types of Waves in Physics

Study Notes

Transverse waves involve particle movement up and down, with crests and troughs as key features. In these waves, the particles of the medium move perpendicular to the direction of the wave propagation. This results in characteristic visuals where crests (the highest points) and troughs (the lowest points) can be observed. Common examples of transverse waves include light waves and waves on strings.
Compressional waves, also known as longitudinal waves, display left and right particle movement, forming areas of compression and rarefaction. In compressional waves, particles of the medium oscillate parallel to the wave direction. This creates areas where particles are crowded together (compression) and areas where they are spread apart (rarefaction). A classic example of compressional waves is sound waves traveling through air or liquids.
Waves transfer energy along with a medium with minimal particle displacement. This means that while waves can move energy across vast distances, the medium's particles occupy relatively fixed positions around their equilibrium states. The energy transfer facilitated by waves is fundamental in various physical phenomena and technological applications, from communication technologies to energy generation.

The crest represents the highest point of a transverse wave, where the maximum displacement of the medium occurs. This point indicates the peak value of the wave's amplitude, which is crucial in determining the wave's energy. Similarly, the trough, the lowest point, corresponds to the minimum displacement.
The speed of sound varies across different media, influencing how sound is transmitted through various substances:
- Air: 334 m/s – sound travels faster in warmer air due to greater particle energy.
- Freshwater: 1,461 m/s – water's denser molecular structure impacts sound speed positively.
- Seawater: 1,490 m/s – the salt content in seawater also plays a role in increasing the speed of sound compared to freshwater.
- Glass: 5,000 m/s – the tightly packed molecules in glass facilitate rapid sound wave transmission.
- Silver: 2,610 m/s – as a metal, silver allows for faster sound transmission due to its conductive properties.
Sonar technology utilizes reflected sound waves for mapping and locating underwater objects. This method employs the principles of echolocation, where sound waves emitted by a device bounce off objects and return to the source, providing valuable information about the location and distance of these objects. It is widely used in navigation, fishing, and underwater exploration.

Sound waves travel faster in deeper water compared to shallow water. The enhanced speed can be attributed to factors such as increased pressure and temperature at greater depths, which allow sound waves to propagate through the medium more effectively.
Refraction alters wave direction due to changes in the medium; sound waves refract when transitioning from air to water. This bending of waves is critical in various applications, such as underwater communication and navigation, as it affects the perceived locations of objects and underwater signals.
Hard surfaces reflect sound well, while soft surfaces absorb sound. This distinction is significant in architectural acoustics, where the types of materials used in a space can affect the sound environment, impacting clarity and reverberation of sounds, which is crucial for concert halls, studios, and other venues.

Volume is determined by amplitude, with larger amplitudes producing louder sounds. The amplitude of a sound wave indicates its energy level; thus, greater amplitude corresponds to louder perceptions of sound, while smaller amplitudes lead to quieter sounds.
Volume is measured in decibels (dB), which is a logarithmic unit representing the intensity of sound. For perspective, a whisper typically registers at around 30 dB, regular speech is about 60 dB, and sounds above 90 dB can lead to potential hearing damage with prolonged exposure. This scale helps in understanding and regulating sound exposure in various environments.
Pitch changes are perceived differently based on movement relative to the sound source, as observed with a passing car. This phenomenon,