week-13-3 - The Doppler Effect A moving source of sound,...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
The Doppler Effect A moving source of sound, such as a car horn, seems to change pitch depending on its motion relative to the listener. As a car passes a stationary observer, the horn’s pitch changes from a higher pitch to a lower pitch.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
4/15/2011 Physics 214 Fall 2010 2 At what point in circular movement does sound change ? What is relative motion between source and listener at these points ? 4C-01 Doppler Effect WHEN THE SOURCE MOVES TOWARD (AWAY FROM) LISTENER, THE FREQUENCY OF SOUND, OR PITCH, INCREASES (DECREASES). Investigating change in sound due to the Doppler effect
Background image of page 2
The Doppler Effect Comparing the wavefronts for a stationary car horn and for a moving car horn illustrates why the pitch changes. When the car is approaching the observer, the wavefronts reaching the observer are closer together. When the car is moving away from the observer, the wavefronts reaching the observer are farther apart. http://www.physics.purdue.edu/class/applets/phe/dopplereff.htm
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Electromagnetic Waves An electromagnetic wave consists of time- varying electric and magnetic fields , in directions perpendicular to each other as well as to the direction the wave is traveling .
Background image of page 4
The electric and the magnetic fields can be produced by charged particles. An electric field surrounds any charged particle. A magnetic field surrounds moving charged particles. A rapidly alternating electric current in a wire generates magnetic fields whose direction and magnitude change with time. This changing magnetic field in turn produces a changing electric field. Likewise, a changing electric field produces a magnetic field, etc Thus a transverse wave of associated changing electric and magnetic fields is produced
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Maxwell predicted the speed of electromagnetic waves in a vacuum using the Coulomb constant k in Coulomb’s law and the magnetic force constant k in Ampere’s law: This was equal to the known value for the speed of light! v k k 3 10 8 m s c 3 10 8 m s Fizeau’s wheel for measuring the speed of light
Background image of page 6
frequencies and wavelengths of electromagnetic waves. Different types of electromagnetic waves have
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/23/2011 for the course PHYS 214 taught by Professor Staff during the Spring '08 term at Purdue University-West Lafayette.

Page1 / 27

week-13-3 - The Doppler Effect A moving source of sound,...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online