Doppler Effect I. Imagine a bug bobbing up and down in the middle of a quiet puddle.

Slides:

Advertisements

Similar presentations

Waves and the Doppler Effect

Advertisements

Chapter 13 Sound.

Chapter 25 Vibrations and Waves General definitions of vibrations and waves n Vibration: in a general sense, anything that switches back and forth, to.

The Doppler Effect Refers to the frequency change in waves as objects move toward you or away from you. As things move toward you – waves become compressed,

Chapter 19 Vibrations and Waves.

Vibrations and Waves Chapter 25. Vibration of a Pendulum  Vibration – a wiggle in time  A vibration cannot exist in one instant, but needs time to move.

Doppler Effect gGE.

The Doppler Effect. Doppler Effect – Change in frequency and wavelength of a wave for an observer moving relative to the source of the wave. Source is.

Doppler Effect & Redshift Gharib ESS

Doppler Effect Physics 202 Professor Lee Carkner Lecture 11.

The Doppler Effect Thursday, October 26, First, a review from yesterday…

The Doppler Effect. Doppler Effect & Sound Christian Doppler Observing the Doppler Effect Christian Doppler Observing the Doppler Effect Christian Doppler.

Have you ever been outside when an ambulance is passing by? Does the pitch of the ambulance sound higher as it approaches you and lower as it moves away?

Doppler's Effect Presented by : - Dr.R.K.Mishra PGT(Phy) JNV, Tenughat

Chapter 3: Sound Wave Intensity of Periodic Sound Waves

Doppler Effect. What sound do you hear when a car races by at the race track? Or when an ambulance/police car speeds by?

DOPPLER EFFECT This is the apparent change in the frequency of a wave motion as noted by an observer when there is relative motion between the source.

Conceptual Physics Chapter 251 Chapter 25 Waves. Conceptual Physics Chapter 252 Vibration of a Pendulum ¤The back-and-forth motion of a pendulum demonstrates.

Doppler Effect.

The Doppler Effect Ch

Mechanical Waves & Sound. Wave Motion Waves are caused by.

Sound and Wave Interference

The Doppler Effect Ch Objectives 1.Describe doppler effect 2.Describe bow waves 3.Describe sonic booms.

Doppler effect and Shock waves Lecture 10 Pre-reading : §16.8–16.9 Please take a clicker and an evaluation form.

Astrophysics and Cosmology The Wavelengths get “squished” in the direction of motion, and “stretched” in the opposite direction. Doppler Shift Longer,

Chapter 19 Vibrations and Waves There are two ways to transmit information and/energy in our universe: Particle Motion and Wave Motion.

Physics 11 n Waves 6 – Doppler Effect. Constructive & Destructive Interference:

Waves. The time it takes for one wavelength to pass is called the period. The number of wavelengths passing at a given time is called frequency.

Sound and the Doppler Effect. Sound Waves Sound is longitudinal compression wave. Despite this fact, we can still convert and remodel sound waves into.

Physics 11 n Mr. Jean n January 4 th, 2012 The plan: n Video Clip of the day n Wave motion n Wave speed n Types of waves n Interference u Demonstrations.

Doppler Effect. As a wave source approaches, an observer encounters waves with a higher frequency. As the wave source moves away, an observer encounters.

Doppler Effect Christian Doppler This apparent change in frequency due to the motion of the source (or receiver) is called the Doppler effect. The.

Getting Ready for Notes Do your Warm Up. Be prepared to discuss with the class. Set up your IAN Notebook with Cornell Notes like the picture below.

Sound Waves. Mechanical Waves Mechanical Waves – waves that need a medium to transport energy and travel through –EX: Sound, Water, Seismic.

What kind of disturbance is produced when we drop a pebble in a pond? Ripples move outward in a _______. How do sound waves travel? They move outward.

SOUND 5 th Six Weeks. Intro to Sound The source of all waves (including sound) are vibrations. In a sound wave, a disturbance causes molecules in a medium.

Chapter 16 Sound. The Production of Sound Waves  Sound is a result of vibrations or oscillations.  Ex: As the prong in the tuning fork swings to the.

Doppler Effect Shift in frequency (high to low) due to the compression of light (or sound) waves in front of a moving object and the expansion of the light.

Range & Doppler Accuracy by Ramya R.

Chapter 19 Vibrations and Waves There are two ways to transmit information and energy in our universe: Particle Motion and Wave Motion.

Science 10 Mr. Jean April 12 th, The plan: Video clip of the day Sonic Booms Properties of sounds & light Radar Guns Doppler Effect.

The Behavior of Waves Wave Speed Remember: Waves change speed when they encounter a boundary and enter a new medium.

Doppler Effect.

Doppler Effect and Sonic Booms

Doppler Effect and Redshift

The Doppler Effect.

Vibrations and Waves.

Properties of Waves Waves have energy and transfer energy when they interact with matter They cannot travel through empty space!

III.) Doppler Effect: an observed change in the frequency of a wave when the source or observer is moving A) Pitch of a sound (how high or low it is) is.

Sound – Beats Superposition leads to beats – variation in loudness.

Moving stars and changing colors

Physics 11 Mr. Jean January 5th, 2012.

Ms. Pacheco South Oldham HS

Unit 1.4 Waves and Sound.

SPH3U THE DOPPLER EFFECT.

Doppler Effect.

Sound – Beats Superposition leads to beats – variation in loudness.

"I love hearing that lonesome wail of the train whistle as the

Doppler Effect Waves and Sound

Doppler Effect.

Physics 1 Unit 3: Waves Part 3:

Doppler Effect.

Doppler Effect Christian Doppler.

The bug in the center of the puddle is bobbing up and down.

Topic 3 – Part III The Doppler Effect

Presentation transcript:

Doppler Effect

I. Imagine a bug bobbing up and down in the middle of a quiet puddle.

Suppose the bug is not going anywhere but is merely treading water in a FIXED position.

The crests of the wave it makes are CONCENTRIC circles,

because the wave SPEED is the same in all directions.

If the bug bobs in the water at a constant FREQUENCY, the distance between wave crests (the λ ) will be the same for all successive waves.

Waves encounter point A as FREQUENTLY as point B. BA

II. Suppose the jiggling bug moves across the water at a speed LESS than the wave speed.

The wave pattern is no longer CONCENTRIC. A B

The centers of the circular crests now move in the DIRECTION of the swimming bug.

Even though the bug maintains the same bobbing FREQUENCY, an observer at B would encounter the crests more often.

AB

The observer would encounter a HIGHER frequency.

This is because each successive wave crest has a SHORTER distance to travel so they arrive at B more frequently than if the bug were not moving toward B.

This change in FREQUENCY due to the motion of the source or receiver sound waves is called the Doppler Effect.

The GREATER the speed of the source, the GREATER the Doppler Effect.

What is the source? Video taken from a car

What is the source?

“Physics on the Job”

BATS Live for the Doppler Effect!!!

People can use the Doppler Effect too ml?CMP=ILC-SearchStories ml?CMP=ILC-SearchStories

III. When the speed of the source in a medium is as GREAT as the speed of the wave it produces, the waves pile up.

IV. When the speed of the source in a medium is GREATER than the speed of the wave it produces, the source “breaks through” the wave barrier.

An F/A-18 Hornet passing through the sound barrier. The water vapor, density and temperature was just right and there just happened to be a camera in the vicinity to capture the moment. Navy Ensign John Gay made this phenomenal photograph on July 7, 1999 while aboard the carrier USS Constallation as Navy Lt. Ron Candiloro flew by.

Break the Barrier!!! The bullwhip or stock whip moves faster than sound. The tip of the whip breaks the sound barrier and causes a sharp crack. The sound barrier was first broken in a vehicle on land in 1948 by a rocket-powered test vehicle at Muroc Air Force Base (now Edwards AFB) in CA. Chuck Yeager was the first person to break the sound barrier in level flight on October 14, 1947 while flying the experimental Bell X-1 at Mach 1. Mach is a ratio of the speed to the speed of sound (i.e. Mach 2 is twice the speed of sound)

This picture shows a sonic boom created by the THRUST SSC team car as it broke the land speed record (and also broke the sound barrier on land).

Something which travels faster than the speed of sound is said to be SUPERSONIC.

This figure shows a bullet travelling at Mach The mach cone and shock wavefronts are very noticeable.

When the CONICAL shell of compressed air that sweeps behind a supersonic aircraft reaches listeners on the ground below, the sharp crack they hear is described as a SONIC BOOM.

The Doppler Effect is the apparent change in FREQUENCY from a source which could be visible light.

If the source moves towards the observer, the waves will appear closer together forming shorter WAVELENGTHS. This is referred to as a BLUE shift since the wavelengths are becoming shorter.

On the other hand, if the source is moving away from the observer, the waves will appear stretched out to longer WAVELENGTHS. This is referred to as a RED shift since the wavelengths are becoming longer.

Red light Blue light

Use of the Doppler shift in astronomy Here is what the spectrum of a star that is moving toward us might look like (somewhat simplified):

Here is what the spectrum of a star that is moving away from us might look like (somewhat simplified):

How it is used in Weather

A. What does it mean when an astronomer reports a galaxy as red-shifted? A red-shifted galaxy implies that the galaxy is moving away from us, resulting in longer wavelengths and lower frequencies of light emitted by the galaxy.

The local Astronomy club wants to create a T-shirt which demonstrates the Doppler Effect. What colors should the front and back be? FRONTBACK