Physics Chapter 11.2: Transmission of Sound

Transmission of Sound

• Sound needs a medium for transmission, and it cannot travel through a vacuum.
• The speed of sound differs in solids, liquids, and gases, with approximate speeds of 300 m/s in air, 1500 m/s in water, 5000 m/s in iron, and 5400 m/s in granite.
• Sound travels at different speeds in different media, with the speed of sound in gases being less than in liquids, and the speed of sound in liquids being less than in solids.

What is Sound?

• Sound is produced by a vibrating source that disturbs neighboring molecules, causing them to vibrate.
• The direction of vibration is parallel to the direction of the sound wave.
• A series of compressions and rarefactions is formed, transferring energy from the vibrating source to the target without a transfer of the medium or matter.
• Sound waves can be represented by three types of graphs: pressure-distance, displacement-distance, and displacement-time graphs.
• The amplitude of a sound wave is the maximum pressure change, and the wavelength is the distance between the centers of two consecutive compressions or rarefactions.

Pitch and Loudness

• Pitch is related to the frequency of the sound wave, with higher frequency sounds having a higher pitch.
• Loudness is related to the amplitude of a sound wave, with larger amplitudes producing louder sounds.
• The frequency of a wave is the number of complete waves produced per second.

Learn about the transmission of sound, including the need for a medium and how speed varies in different materials. Discover methods for determining the speed of sound in air.