Travelling Waves

Tuesday, 29 May 2018

3:01 PM

A wave is a periodic disturbance that transports energy between two points in space

 

There is no accompanying transfer of matter

 

All waves carry energy, but the amount of energy, and the mechanism of transport depends on the type of wave

 

Mechanical Wave

(ie sound waves)

Propagation requires a medium

  • Requires a source of disturbance (ie flick a rope)
  • Requires a medium that can be disturbed (the rope)
  • Requires some physical coupling mechanism (tension)

 

Electromagnetic waves
(ie light, xrays)

Propagation does not require a medium

 

Matter waves

(particles)

 

 

Pulses

A pulse is not periodic, but is very similar to a wave

  • A pulse carries energy
  • A pulse has a definite height
  • A pulse has a definite speed of propagation
  • A pulse does not change shape as it travels

A periodic pulse is a wave..?

 

 

Transverse - displacement perpendicular to the direction of propagation

Longitudinal - displacement parallel to the direction of propagation

 

 

 

EM waves are also transverse waves, however they have no medium - it is the electric and magnetic fields that oscillate in directions perpendicular to the direction of propagation.

Machine generated alternative text: Transverse waves>EM waves... . Electromagnetic waves are also transverse waves, although in this case there is no disturbed medium. -It is the electric and magnetic fields that oscillate in directions perpendicular to the direction of propagation. z wave dil Red = Electric field Blue - — Magnetic field

 

 

 

Sound Waves (Longitudinal)

Sound waves are mechanical waves that disturb the air density and pressure

 

 

Created with Microsoft OneNote 2016.