information about waves

Wave is a transfer of energy, in the form of disturbance through some medium, without translocation of the medium. A wave having a shortduration is called pulse. Waves that vibrate in repeating cyclesillustrate periodic motion or harmonic motion. One complete oscillation is called cycle.

Transverse vibration occurs when vibration of the medium is perpendicular to the direction of energy transfer. The maximum andminimum positions on a transverse wave are called the crest and trough.

Longitudinal vibration occurs when the medium vibrates parallel to thedirection of energy transfer. Longitudinal vibrations consist ofregions of compression and rarefaction.
Frequency (f) describes the number of cyclesoccurring in a given unit of time. The SI unit for frequency ishertz (Hz). The units cycles / second are also used.Frequency = Number of cycles / Time Interval
Period (T) is the time required to completeone full cycle. Period and frequency exhibit a reciprocal relationship.The amplitude of a wave is the maximum displacement from theequilibrium or the rest position.

Wavelength (l) is the distance betweensuccessive crests or successive troughs. The wavelength is the shortestdistance between two points in phase (or two points that have identicalcharacteristics). The universal wave equation(v = fl) is saidto be universal because it applies to all types of waves. The universalwave equation can be used to solve various problems relating to wavemotion.

Reflection of Waves. When a series of waves strikes an obstacle,the waves are reflected. Waves falling upon the barrier are calledincident waves and waves reflecting from the barrier are calledreflected waves. Reflection of waves can be summarized in the followinglaw of reflection: the angle of incidence(q_i) isequal to angle of reflection (q_r).Here is a diagram illustrating the reflection of waves:
Refraction of Waves. Refraction occurs at the boundary betweentwo different media and causes the waves to change direction as shownin the following diagram:
Diffraction of Waves. Diffraction is the bending that occurswhen a wave passes around the edge of an obstacle. Waves having longerwavelengths are diffracted more than those with shorter wavelengths.When waves pass through a slit, diffraction is maximized when thewavelength and the slit width are within the same order of magnitude.