/
Doppler Effect, Bow Waves, and Shock Waves Doppler Effect, Bow Waves, and Shock Waves

Doppler Effect, Bow Waves, and Shock Waves - PowerPoint Presentation

kittie-lecroy
kittie-lecroy . @kittie-lecroy
Follow
434 views
Uploaded On 2017-03-24

Doppler Effect, Bow Waves, and Shock Waves - PPT Presentation

Doppler Effect apparent change in frequency of a wave due to the motion of the source of the wave If the object is moving towards the observer the frequency will appear to increase If the object is moving away from the observer the frequency will appear to decrease ID: 529061

waves wave moving frequency wave waves frequency moving sound speed faster person high doppler source object pitch strong hitting

Share:

Link:

Embed:

Download Presentation from below link

Download Presentation The PPT/PDF document "Doppler Effect, Bow Waves, and Shock Wav..." 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.


Presentation Transcript

Slide1

Doppler Effect, Bow Waves, and Shock WavesSlide2

Doppler Effect

~apparent change in frequency of a wave due to the motion of the source of the wave.

If the object is moving towards the observer the frequency will appear to increase

If the object is moving away from the observer the frequency will appear to decreaseSlide3

Why does this happen

Frequency- number of waves to pass by in a second.

Waves travel out from their source in rings, like when a stone is thrown in a pond.

This person should have the same number of waves hitting them each second

As this person

Will.Slide4

But if the source is moving

Each new wave will start in a different place than the last wave.

This person now has less waves hitting them each second

than this person

Will.

. . . . . . . .

Each dot shows the

where the source was

when that wave was

madeSlide5

Observable traits of frequency

Sound frequency is observed as the pitch.

High frequency high pitch (dentist drill), low frequency low pitch (bass drum)

Light frequency is color

Low freq- Red OYGBI violet- high freq

Moving towards

Moving away fromSlide6

With Light…

It causes red shift (moving away from you) and blue shift (moving towards you) in stars.

But with out an

extremely

high speed it is not noticeable to the human eye

You need sensitive equipment to notice a frequency change

Like Dual Doppler XL or Doppler 2000 With this radar you can check the motion of a storm Slide7

What if an object is moving faster than the waves they are producing

The front edge of the

New wave will be

Ahead of the last

Wave!

It also creates

This pattern

Of strong

Waves at the

edges

here

And here

By strong I mean

Larger amplitude

A whole bunch of waves

Hit at once causing constructive interferenceSlide8

Where does this occur

Two dimensionally this is called a

Bow Wave

.

It commonly occurs on a speed boat

Three dimensionally this is called a Shock Wave.It occurs in supersonic jets (ones that go faster than the speed of sound)When that strong wave hits you, you hear a

sonic boom (all of the sound hitting you at once)Slide9

Sound Barrier

There is an actual “barrier” to moving at the speed sound.

When you hit the speed of sound (or any wave you are making) you hit all of those waves you just made.

All of that interference causes a turbulence.

This goes away if you are moving faster than sound.

A sonic boom is heard by observers whenever an object moves faster than sound not just when it crosses the threshold