doppler effect experiment (1 Viewer)

[Leah.Midd]

does anyone no or can u reccomend an experiment to demonstrate the doppler effect???

 

[helper]

It isn't in the syllabus but the easiest examples are:
Listining to a car as it approaches you and goes past. Have the person put there hand on the horn to make it better
Swing a whistle around your head. Have an observer listen to the change in pitch as it approaches and goes away from them.

You want to go further, use a sound sensor to capture the sound and analyse the waveform to observe the shift.

 

[Leah.Midd]

It isn't in the syllabus but the easiest examples are:
Listining to a car as it approaches you and goes past. Have the person put there hand on the horn to make it better
Swing a whistle around your head. Have an observer listen to the change in pitch as it approaches and goes away from them.

You want to go further, use a sound sensor to capture the sound and analyse the waveform to observe the shift.

yeha i no it isnt in the syllabus but our teacher has still set it as an assessment task....i need to use numbers and measurements, if u got anythign a bit more detailed would b helpfull?

 

[helper]

In class or at home?

If at home:
Record something that demonstrates the doppler effect.
Import you sond onto your computer

Download and install a free frequency analyzer.
http://www.hitsquad.com/smm/win95/SPECTRUM_ANALYZERS/

Identify a point of time when the object is coming towards you. Determine the frequency.
Identify a point of time when the is moving away from you. Determine the frequency.
Identify a point of time when the source is stationary compared to you. Determine the frequency

A buzzer giving off a constant sound would be a good sound source to use.

If at school use a CRO or datalogger to take readings and then measure wavelength.

Otherwise if its acceptable there are lots of applets that you can take readings of.

Example of my first idea
http://www.physics.ubc.ca/~outreach/phys420/p420_03/marissa/demo.htm

Or you could do it with a slinky.

 

[Leah.Midd]

awesome, thanks heaps!!

 

[Kant]

Hmm, a small trolley with a sound source on it, travelling at around 0.5ms-1 would probley do. Need a pulley, some cable and would need to build the small trolley, maybe wield one together. Make a constant tone with Cool Edit Pro, record it to CD and mount it on the trolley and play the sound via cd player.

or

How about a ball rolling down a tube, a sound source beams the rolling ball and reflects it back?
You would get 2 peaks on the oscilloscope. The "true" frequency and the reflected freq., Like sonar.You compare the differences between the peaks.

 

[Leah.Midd]

Hmm, a small trolley with a sound source on it, travelling at around 0.5ms-1 would probley do. Need a pulley, some cable and would need to build the small trolley, maybe wield one together. Make a constant tone with Cool Edit Pro, record it to CD and mount it on the trolley and play the sound via cd player.

or

How about a ball rolling down a tube, a sound source beams the rolling ball and reflects it back?
You would get 2 peaks on the oscilloscope. The "true" frequency and the reflected freq., Like sonar.You compare the differences between the peaks.

hey ur a thinker!!!!good work adam!

 

[DigitalFortress]

Get a formula 1 race on TV.

Notice the change in pitch of the engines on the straights as the cars move close to the camera and as they move away....

 

[Leah.Midd]

does anyone know of any programs that i can use to calculate the frequency of the sound??

 

[boyle777]

cool. Btw henry t says hi guys!