Waves and Sound

Flashcards on Waves and Sound

Wave

A traveling disturbance that carries energy from place to place without bulk movement of matter.

Transverse Wave

A wave in which the disturbance happens in a direction perpendicular to the direction of motion of the energy in the wave.

Longitudinal Wave

A wave in which the disturbance happens in a direction parallel to the direction of the motion of the energy in the wave.

Periodic Wave

A wave in which the disturbance pattern repeats exactly over an extended length of time.

Wavelength

The horizontal length of one cycle of a periodic wave.

Period (T)

The time required for one complete cycle of a wave. (Unit: s)

Frequency (f)

The number of cycles of a wave which are completed in 1 second. (Unit: s-1 or Hz)

Amplitude (A)

The maximum range of the disturbance from the undisturbed position.

Peak-to-peak Amplitude (Ap-p)

The vertical distance from the peak of a wave to its trough, equal to 2A.

Wave Speed (v)

The speed at which the energy is transported along the direction of propagation of the wave.

Sound Wave

Consists of a series of compressions and rarefactions of the medium carrying the sound and are longitudinal waves.

Sound Intensity (I)

The power that passes perpendicularly through a surface divided by the area of that surface. Unit: W/m2

Threshold of Hearing

The smallest sound intensity that the human ear can detect, approximately 1x10-12 W/m2 for a 1000 Hz tone.

Decibel (dB)

A measurement unit used when comparing the loudness of two sound intensities, using a logarithmic scale.

Pitch

The frequency of a sound wave.

Quality (Timbre)

The characteristic of a sound wave determined by the presence of multiple frequencies.

Doppler Effect

The change in frequency or pitch of the sound detected by an observer because the sound source and the observer have different velocities with respect to the medium of sound propagation.