Vernier Software and Technology
Vernier Software & Technology

Doppler Effect: Surface Water Waves

Introduction

Have you ever noticed that when a train or car moves past you rapidly its whistle or horn seems to change to a lower note? In 1842 an Austrian Physicist, Hans Christian Doppler, asserted that sound waves emitted by a moving train would have a higher frequency when moving toward a listener and a lower frequency when moving away. For surface waves in water, Doppler predicted the same type of frequency shift. In particular, a decrease in the frequency of waves propagating behind a source that moves away at a speed vs can be predicted using the Doppler equation

{f_{\text{B}}} = {f_0}\frac{{{v_{\text{w}}}}}  {{{v_{\text{w}}} + {v_{\text{s}}}}}

where vw is the speed of wave propagation in water and f0 is the frequency of the waves created by a stationary source. Doppler also predicted that the frequency increase in front of a source is given by

{f_{\text{F}}} = {f_0}\frac{{{v_{\text{w}}}}}  {{{v_{\text{w}}} - {v_{\text{s}}}}}

Objectives

In this activity, you will

  • Verify the Doppler Equations for surface waves in water by using Logger Pro to analyze two high speed movies.

Software for Experiment

This experiment uses Logger Pro software for video analysis. The video for analysis is included with the lab book.

Physics with Video Analysis

See other experiments from the lab book.

1Rolling Ball
2Big and Small: How to Scale an Image
3Velocity Change
4Velocity and Speed
5Velocity and Acceleration
6Three Movies: Determining Constant Acceleration
7Demon Drop: A Mathematical Modeling Activity
8Jumping on the Moon
92D Vectors: Pool Ball Displacement, Velocity, and Speed
10Galileo's Projectile I: Using 17th Century Techniques
11Galileo's Projectile II: Using Contemporary Techniques
12Projectile Motion Vectors
13Frictional Slowing
14Impulsive Juggling
15Center of Mass Motions
16Finding a Spring Constant
17Net Work - Kinetic Energy Theorem
18Oscillations
19Slinky Wave Speeds
20Superposition of Slinky Waves
21A Wave Pulse Equation
22Doppler Effect: Surface Water Waves
23Doppler Effect: Sound Waves
24A Heat Engine: Relating Work to the P-V Cycle
25Coulomb's Law for Two Charged Spheres
26Discharge Rate
27Electric Field Due to a Line of Charge
28Resistance and Ohm's Law
29Parallel Plate Capacitor: Potential Difference vs. Spacing
30Wiring Capacitors in Series and Parallel
31Using RC Decay to Determine Capacitance
32Exploring Faraday's Law
33Snell's Law of Refraction

Experiment 22 from Physics with Video Analysis Lab Book

<em>Physics with Video Analysis</em> book cover

Included in the Lab Book

Vernier lab books include word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.

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