A wave is a vibration That travels from place to place Thus it is two motions each with its own direction The Vibration a SHM The Propagation its motion from place to place Together they from a wave ID: 803423
Download The PPT/PDF document "Waves Chapter 11 part 2 Definition of a ..." is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Waves
Chapter 11 part 2
Slide2Definition of a Wave
A wave is a vibration
That travels from place to place
Thus it is two motions each with its own direction
The
Vibration
: a SHM
The
Propagation
; its motion from place to place
Together they from a wave
Slide3Wave Types, by medium
A vibration requires something to vibrate,
a “
medium
”
There are two types:
Mechanical
: the medium has mass, such as…
Waves on a slinky, rope, water surface, sound etc.
Non-mechanical
: such as…
Light, an electromagnetic wave
and
Gravity waves… a wave in space and time itself
(Gravity waves were recently detected an are no longer only theoretical!
Slide4Types by Relative Direction
If the directions of propagation and vibration are perpendicular, it is
transverse
wave
Example: Ocean Wave, Wave on Rope
If the directions of propagation and vibration are parallel it is
longitudinal
wave
Example: Sound
Slide5Parts of a Wave
As a wave is a vibration it has the properties of a vibration…plus one more
Its wavelength (
λ
), how far it goes during one cycle of vibration
Slide6Speed of a wave
The speed of a wave is determined by its wavelength and frequency
V = f
λ
Slide7Interference
What happens when two waves meet
Constructive
Waves meet in phase
Amplitude increases
Destructive
Waves meet out of phase
Amplitude decreases
Perhaps even canceling!
Slide8Reflected Waves
When a Wave reflects at a fixed boundary
It becomes inverted
When a Wave reflects at a boundary where its is free to move
It does not
Slide9Standing Waves
If waves are sent through a medium at the right frequencies
Reflected wave interfere with the new waves
Constructively and destructively at consistent places
Making a “stationary”
Or
Standing Wave
Points of no vibration are called
Nodes
Points of maximum vibration are
called
Antinodes