The Doppler Effect The Doppler Effect The Doppler

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The Doppler Effect

The Doppler Effect

The Doppler Effect

The Doppler Effect

The Doppler Effect Imagine a bug jiggling its legs and bobbing up and down

The Doppler Effect Imagine a bug jiggling its legs and bobbing up and down in the middle of a quiet puddle

Doppler Effect What would happen to the waves if the bug began to swim

Doppler Effect What would happen to the waves if the bug began to swim forward, toward B?

Doppler Effect What does that do to the frequency of the waves, in front

Doppler Effect What does that do to the frequency of the waves, in front of the bug and behind the bug? In front of the bug…the frequency ↑ Behind the bug…the frequency ↓

Animation of the Doppler Effect � http: //www. fearofphysics. com/cgibin/doppler. cgi? dir=t&vs=200&mode=wrap

Animation of the Doppler Effect � http: //www. fearofphysics. com/cgibin/doppler. cgi? dir=t&vs=200&mode=wrap

If the frequency of sound changes…what also changes? Pitch…. A man’s vocal chords vibrate

If the frequency of sound changes…what also changes? Pitch…. A man’s vocal chords vibrate slower than a woman’s…hence a lower voice=lower pitch

Sound and the Doppler Effect The Doppler effect causes the changing pitch of a

Sound and the Doppler Effect The Doppler effect causes the changing pitch of a siren In front of the car… the pitch ↑ Behind the car… the pitch ↓

The Doppler Effect is a change in pitch…due to a change in frequency Note:

The Doppler Effect is a change in pitch…due to a change in frequency Note: The change in loudness is not the Doppler Effect! It is the shift in frequency! http: //www. youtube. com /watch? v=Y 5 Kae. CZ_Aa Y

The Doppler Effect and RADAR Police use the Doppler effect of radar waves to

The Doppler Effect and RADAR Police use the Doppler effect of radar waves to measure the speeds of cars on the highway

The Doppler Effect and RADAR guns 2011, Aroldis Chapman reached back and threw a

The Doppler Effect and RADAR guns 2011, Aroldis Chapman reached back and threw a pitch to Andrew Mc. Cutchen of the Pirates. The pitch wound up being high and tight, not a location necessarily to be proud of, and yet he received a standing ovation. Why the standing ovation, you may ask? The stadium radar reading displayed a velocity of 106 MPH, a speed that has only been topped twice since baseball started recording pitch velocities.

Doppler RADAR

Doppler RADAR

Sheldon Cooper � http: //www. youtube. com/watch? v=Y 5 Kae. CZ_A a. Y

Sheldon Cooper � http: //www. youtube. com/watch? v=Y 5 Kae. CZ_A a. Y

The Doppler Effect � Named after Christian Doppler (Austrian) 1803 -1853

The Doppler Effect � Named after Christian Doppler (Austrian) 1803 -1853

Review When a source moves toward you, do you measure an increase or decrease

Review When a source moves toward you, do you measure an increase or decrease in wave speed? Neither! It is the frequency of a wave that undergoes a change, not the wave speed.

Review How does the apparent frequency of waves change as a wave source moves?

Review How does the apparent frequency of waves change as a wave source moves? The sound waves become more frequent (compressed together). The sound waves become less frequent (stretched apart).