what is a good way to demonstrate the doppler effect?
603387
A novel experiment to demonstrate doppler shifting\n\n\n\nA novel experiment to demonstrate doppler shifting\nThere are many everyday examples of the Doppler effect - the changing pitch of police and ambulance sirens, train whistles and racing car engines as they pass by. \n\nIn each case, there is an audible change in pitch as the source approaches and then passes an observer. The effect arises because sound waves arrive at the listener's ear closer together as the source approaches, and further apart as the sound waves recede. The faster the object is moving, the greater the effect.\n\nTo illustrate the Doppler shift and the effect that the distance to the source has on it, Jean-Pierre Lebreton performed the following simple experiment:\n\nA video camera recorded a scooter, blaring its horn, approaching and passing by the cameraman. Two recordings were made; the first one while the cameraman was standing close to the road on which the scooter was driving, the second one some distance away from the road. The video clips and associated sound files are featured below. The sound files were analysed with an audio analysis programme (see the related links) and the result of the analysis is shown in the graph to the right of each video clip.\n\nThe graphs show the spectral analysis of the signal. The main horn frequency is just below 4000 Hz, but you can see that the horn spectrum is rich in harmonics. Note the fast change in tone (frequency) at around 7 seconds in the top graph - this is around the point when the scooter passes the cameraman. Before that point, the scooter was approaching the cameraman (the frequency increases); after that, the scooter was moving away (the frequency decreases). \n\nThe bottom graph shows a much smoother frequency change. This is because the Doppler effect depends on the relative movement toward or away from the observer, not on absolute movement. With increasing distance between the source (the scooter) and the observer (the cameraman), the relative movement towards or away from the observer becomes smaller and thus the Doppler shift diminishes.
1105659
D'un point de vue mathématique, calculer la vitesse de la balle revient à résoudre un système de n équations différentielles avec conditions initiales. C'est un peu laborieux, donc dans la pratique on utilise effectivement un radar à effet Doppler, le plus souvent sous forme de canon.\n\n Ce radar est pourvu d'un émetteur à radio-fréquences (dans la gamme des micro-ondes) dont les ondes sont réfléchies par la balle en déplacement. Le délai de retour de l'onde est proportionnel à la vitesse de la balle. Ce délai est amplifié, filtré et analysé par une puce DSP qui pratique une correction d'erreurs et envoie les données analogiques à l'afficheur. \n\nA noter que les joueurs amateurs peuvent eux aussi chronométrer leur coup droit, grâce à un module de type Speed Trac qui s'accroche sur le filet. Ludique et pas trop cher.
1021996
try this tracking applet:\nhttp://science.nasa.gov/Realtime/JTrack/Spacecraft.html
998189
ok, you could choose how light waves chance in different colors, and make it interesting with examples of real life. You could also talk about the light properties like reflection, refraction, dispersion, diffraction and interference. Always remember to show an example from day to day life.
158584
Try,\n\nhttp://www.personal.psu.edu/faculty/d/x/dxh40/MBLemma.pdf
849482
Have you thought about using FFT (Fast Fourier Transform)? That should be easy to implement.
946504
Intensity varies as the square of the distance.\nThat should help
899180
In the direction of the velocity vector. That's the best that can be done, given the limited information you have provided.
405837
You need to have recorded the power over a range of frequencies and ploted the Output over the Input. If the chirp signal can be extrapolated into its freqency components possibly you can compare the output to this, otherwise a new set of data points are required.
707699
Well for sund waves you can use the tuning fork and cup of water demonstration. As the water absorbs the sound waves it will ripple with the same vigor as the tuning fork. As far as light waves you can use the same glass and direct a flashlight through it to show how the water bends the light. Hope this helps.
161310
Motion towards or away from the observer. This motion in effect changes the wavelength of the light emitted by the star, and it's wavelength that determines the color of light.\n\nA picture is worth a thousand words, so check the animated graphics at this website:\nhttp://www.colorado.edu/physics/2000/applets/doppler.html\n\nNOTE..!  The graphics at the website are for sound waves, but light waves behave the same way.
1101763
Well....moving water has a different refractive index to still water. So if you can monitor the intensity of color using the color of the light from still water you will see a change in the color when the water is moving. It is then possible to see that movement in the water is taking place. \nThe speed of movement maybe be also indexed as a change in refractive index. \nSo, it would be possible to run some controlled experiments and determine convection of water in some form of useful units.
24203
The 'Doppler Shift' indicates the color or wavelength of light.  Light traveling toward you would be more in the red end of the spectrum, while light traveling away would be more in the blue end.
143763
a signal emmited in the band of the 2 GHz.
118141
I think experiments examining the Doppler Effect are always appropriate.
556899
An animation flash demo with stepwise calculation is given\nhttp://www.technocs.vipzone.biz
437661
This requires the use of doppler shift formula for a moving source and stationary observer:\n\nf = f0 ( v / ( v + u ) )\n\nf0 = actual frequency = 5\nv = speed of wave = 20\nu = relative velocity of source away from observer = -10\n(since travelling toward)\n\nf = observed frequency = 10 Hz\n\nNow velocity = v = fl = frequency * wavelength\n\nso wavlength l = v / f = 20 / 10 = 2m