This course gives introduction on different types of sound and waves.
Anything that vibrates is producing sound; sound is simply a longitudinal wave passing through a medium via the vibration of particles in the medium.
Consider a sound wave traveling in air. This sound wave is generated by a speaker broadcasting a single frequency, so the speaker cone is oscillating back and forth in simple harmonic motion. The motion of the speaker slightly changes the pressure in the air next to it. When the speaker moves out, the air is compressed more than average and the pressure increases; when the speaker moves in, the pressure decreases slightly. These pressure changes propagate away from the speaker, and this is what a sound wave is, a pressure wave.
A wave is a disturbance that transfers energy from one place to another without requiring any net flow of mass. Waves can be broadly separated into pulses and periodic waves. A pulse is a single disturbance while a periodic wave is a continually oscillating motion. There is a close connection between simple harmonic motion and periodic waves; in most periodic waves, the particles in the medium experience simple harmonic motion.
Waves can also be separated into transverse and longitudinal waves. In a transverse wave, the motion of the particles of the medium is at right angles (i.e., transverse) to the direction the wave moves. In a longitudinal wave, such as a sound wave, the particles oscillate along the direction of motion of the wave.
Surface waves, such as water waves, are generally a combination of a transverse and a longitudinal wave. The particles on the surface of the water travel in circular paths as a wave moves across the surface.
Anything that vibrates is producing sound; sound is simply a longitudinal wave passing through a medium via the vibration of particles in the medium.
Consider a sound wave traveling in air. This sound wave is generated by a speaker broadcasting a single frequency, so the speaker cone is oscillating back and forth in simple harmonic motion. The motion of the speaker slightly changes the pressure in the air next to it. When the speaker moves out, the air is compressed more than average and the pressure increases; when the speaker moves in, the pressure decreases slightly. These pressure changes propagate away from the speaker, and this is what a sound wave is, a pressure wave.