Acoustics - Science
Points to Remember
· Wave velocity is the velocity with which the wave travels through the medium.
· Velocity of a sound wave is maximum in solids because they are more elastic in nature than liquids and gases. Since gases are least elastic in nature.
· Infrasonic waves are sound wave with a frequency below 20 Hz. A human ear cannot hear these waves.
· Ultrasonic waves are sound waves with frequency greater than 20 kHz, A human ear cannot detect these waves.
· Reflection of sound waves obey the laws of reflection.
· when a compression hits the boundary of a rarer medium, it is reflected as a rarefaction.
· An echo is the sound reproduced due to the reflection of the original sound wave.
· The minimum distance between the source and the reflecting surface should be 17.2 m to hear an echo clearly.
· “The apparent frequency” is the frequency of the sound as heard by the listener.