Sound Wave as a Longitudinal Wave
Sound wave is a series of compression and rarefaction of layers of air molecules repeatedly through space.
The forward and backward vibration of the air molecules in the direction of motion of a sound wave shows that sound is a longitudinal wave.
Types of Sound Wave
Speed of Sound Wave
Pitch and Loudness
Loudness is influenced by the amplitude of the sound wave.The greater the amplitude of sound wave, the higher the loudness of the wave.
The pitch of a sound is high or low of the sound. The pitch of sound is determined by its frequency. The higher the frequency, the higher the pitch.
Refraction of Sound Wave 1
The amplitude of the sound wave increases when a balloon filled with carbon dioxide is placed between the speaker and the microphone.
Refraction of Sound Wave 2
The amplitude of the sound wave decreases when a balloon filled with helium gas is placed between the speaker and the microphone.
Refraction - Natural Phenomenon
The sound of a distance train is clearer at night.
Sound wave travel slower in cool air. As a result, the sound wave is refracted in the path of curve towards the ground instead of spreading to a wider area (as at daytime).
Diffraction of Sound Wave
The street cleaner can hear the sound of the radio even though it is behind an obstacle.
Card 11: Interference of Sound Wave
Interference of Sound Wave
Alternating loud and soft sounds are detected as the microphone is moved from left to right.
Card 12: Interference of Sound Wave - Formula
Formula of Interference
Wavelength of the sound wave is given by the equation