Chapter 16

Waves velocity and energy

Transverse and longitudinal waves

Two ways to put the wave on paper

Wavelength and frequency

Mathematical representation of a wave

Wavelength and frequency

Mathematical representation of a wave

Wavelength and frequency

Mathematical representation of a wave

Wavelength and frequency

Mathematical representation of a wave

Wavelength and frequency

Mathematical representation of a wave

Wavelength and frequency

Mathematical representation of a wave

Wavelength and frequency

Mathematical representation of a wave

Wavelength and frequency

Mathematical representation of a wave

Wavelength and frequency

Mathematical representation of a wave

Wavelength and frequency

Angular wave number and angular frequency

Wavelength and frequency

Angular wave number

distance

dis

pla

cem

en

t

Wavelength and frequency

Angular frequency

time

dis

pla

cem

en

t

Phase constant

Change in syllabus

20

Speed of a travelling wave

Speed of a travelling wave

What determines the direction of the wave propagation

What is the speed of the wave

Speed of a travelling wave

=

Speed of the wave

1(1, 1) = sin(1 1)

=

Wave is moving in positive direction.

2(2, 2) = sin(2 2)

(1 1) = (2 2)

Speed of a travelling wave TO THE LEFT

(, ) = sin( + )

=

Wave is moving in negative direction.

() =

+ =

=

=

= f

Direction of motion of a travelling wave: SUMMARY

Arbitrary shape running wave

In-phase and out-of-phase

distance

dis

pla

ce

me

nt

two particles are in phase if they have the same displacement and are moving in the same direction.

in-phase in-phase

out-of-phase

wavelength

wavelength

two particles separated by one wavelength move in-phase.

wavelength

two particles separated by HALF wavelength move out-of-phase.

Transverse speed and acceleration

Transverse speed and acceleration

The speed of a wave is set by the properties of the medium.

tension in a string

= / linear density of the string

The wave speed is one wavelength per period the wave moves a distance of one wavelength in one

period of oscillation.

=

Speed of a travelling wave

Example 3