Waves

WAVESKinds and Properties

What are WAVES?

Wave is propagation of disturbance through a medium or space by which energy is transferred.

A single unrepeated disturbance is called wave pulse.

A succession of periodic disturbanceis called wave train.

Kinds of Waves

According to the direction of motion- transverse wave- longitudinal waves

According to the presence of medium- mechanical waves- electromagnetic waves

Transverse Waves are waves in which particles

move in a direction perpendicular to the direction of the waves

Longitudinal Waves are waves in which particles move in the

direction parallel to the direction of the waves.

Mechanical Wave requires a medium for the transport of energy medium can be in solid, liquid or gaseous

state examples: sound waves, earthquake/seismic

waves, tidal waves

Electromagnetic Wave

can transmit energy without material or medium

can move in an empty space examples: light waves, radio waves

Electromagnetic Wave

Electromagnetic Wave

Amplitude

Is the max distance that a wave will travel away from the rest position

Example, p. 12 In transverse waves the amplitude is

measured by the up and down motion (crest and trough)

In longitudinal waves the amplitude is measured by how compressed or rarefied the medium is (more compressions, the stronger the wave)

Wavelength

The distance between two corresponding parts of a wave is its wavelength Transverse waves are measured from crest

to crest or trough to trough Longitudinal are measured by the length of

the compressions

Frequency

Is the number of complete waves that pass a given point in an amount of time

Frequency can be increased and decreased

Frequency is measured in hertz Hertz are measured by waves per second Example, if a wave passes through a point

on a rope 2 times in one second, it would have a frequency of 2 Hz

Speed

Speed, wavelength, and frequency are all related Speed = Wavelength x Frequency

If you know two of the quantities in this formula you can solve for the other (just like Ohm’s law) Frequency = Speed/Wavelength Wavelength = Speed/Frequency