Physics Kenya
Sound
Sound
Sound
Sound: nature and sources (experimental treatment required)
Sound is oscillation in pressure, stress, particle displacement, particle velocity, etc., propagated in a medium with internal forces (e.g., elastic or viscous), or the superposition of such propagated oscillation.
The sources of sound
- vibrating solids.
- rapid expansion or compression (explosions and implosions).
- Smooth (laminar) air flow around blunt obstacles may result in the formation of vortices (the plural of vortex) that snap off or shed with a characteristic frequency. This process is called vortex shedding and is another means by which sound waves are formed. This is how a whistle or flute produces sound. Also the aeolian harp effect of singing power lines and fluttering venetian blinds.
Propagation of sound: compressions and rarefactions
Speed of sound by echo method
Sound can travel in air (gases), liquids and in solids. Sound is a mechanical wave hence can not travel in vacuum. The speed of sound in air is approximately 340 m/s. The speed of sound in air changes with temperature. As the temperature increase the speed of sound also increases. Sound travel faster in solids than in liquids and air.
Factors affecting speed of sound
Problems on velocity of sound
Listening to this topic
