Waves3

Waves3 - Transcript

Wave Wave
a disturbance that propagates that through a material medium or space through medium space In order for a mechanical wave to exist In mechanical energy is needed to create a energy disturbance in an elastic medium disturbance elastic Waves transfer energy without Waves transfer the bulk transport of matter

No medium is needed for No ELECTROMAGNETIC waves waves Light radio x rays and gamma rays are some examples of e m waves are All e m waves travel through free All travel space at a speed of approximately 3 00 x 108 m s or 186 000 miles sec or This speed is known as the speed of light light

TRANSVERSE
The displacement of the particles The of the medium is perpendicular to perpendicular to the direction of wave propagation

LONGITU DINAL
The displacement of the particles of the medium is parallel to the is parallel to direction of wave propagation

SU RFACE
A combination of combination transverse and longitudinal transverse longitudinal Click here here and here to view simulations of transverse and longitudinal waves

Amplitude Amplitude the maximum displacement the maximum of a particle of the medium from of the rest or equilibrium position
denoted by A and measured in units of length

Phase Phase related to the position and motion related position of the particles of the medium

Wavelength Wavelength the shortest distance between the shortest two points that are in phase
denoted by and measured in units of length denoted

Frequency the number of complete Frequency
vibrations per unit time vibrations denoted by f and measured in units of Hz

Period the shortest time interval during time
which the motion of the wave repeats which itself itself denoted by T and measured in units of time

T 1 f



f 1 T

Velocity the speed of the wave speed Velocity
denoted by v and measured in units of dist time The speed of a wave depends on the The properties properties of the medium through which it is traveling

v d t T f

Reflection
the turning back of a wave when the turning it reaches the boundary of the it boundary medium through which it is traveling

Law of Reflection
the angle of incidence is equal the angle equal to the angle of reflection to angle

There are two types of reflection Fixed end Termination the reflected wave is inverted when it reflects from a more dense medium Free end Termination the reflected wave is upright when it reflects from a less dense medium
Click here to view these types of Click here reflection reflection

the bending of a wave as it bending passes obliquely from one obliquely medium into another of different propagation speed different

Refraction

For refraction to occur the wave must change speed and must enter the new medium at an oblique angle

Diffraction Diffraction
the spreading of a wave spreading of around a barrier or through an opening

Interference
the result of the superposition the superposition of two or more waves

Superposition Principle
the displacement of the medium when two or more waves pass through it at the same time is the algebraic it algebraic sum of the displacements caused by the individual waves

Types of Interference
Constructive Constructive results in a larger amplitude larger Destructive results in a smaller amplitude smaller

Read more about interference here here Click here to view the interference Click here pattern resulting from the superposition of two transverse waves Click here and here to view Click here here simulations of the interference of two circular waves

The ripple tank simulation found here can be used used to investigate wave properties
You can view reflection You refraction diffraction and interference using both plane and circular waves Click here to view a movie Click here clip of an actual ripple tank experiment

A standing wave is the standing result of two wave trains of the same wavelength frequency and amplitude traveling in opposite directions through the same medium

Learn more about standing waves here here and here Click here to view a simulation of the interference of two traveling waves that can result in a standing wave Click here to view a simulation of standing waves on a string

Standing waves may be produced easily in water string and air columns

Doppler Effect Doppler
the change in frequency due to the relative motion of the wave source and the observer

The observed frequency is higher when the The observed higher source and observer are getting closer source closer The observed frequency is lower when the The observed lower source and observer are getting farther away source away

Click here here here and here here here here and here to run simulations of the Doppler Effect

The Doppler Effect can be evident for all types of waves including light sound water etc