Doppler Effect Simulation
Name___________________________
8th Grade PSI
Score _________/ 26 points
Purpose- Explore the basics of the Doppler Effect by studying the frequency that
cannonballs strike a target during various scenarios.
Materials- Internet Ready Device with JAVA.
Procedure Go To http://carma.astro.umd.edu/AWE/Doppler/redshift.html
 Follow the directions for each section, make observations, and write
explanations of each using your knowledge of the Doppler Effect.
Part 1 - Stationary Cannon & Stationary Target
 Click start simulation. Compare the frequency that the cannon fires the
cannonballs to the frequency that they hit the target.
Observations:
Explanation:
Part 2 - Moving Cannon Toward Target & Stationary Target
 Click Reset Simulation. Select “Shooter motion” moving toward target.
Click start simulation. Compare the frequency that the cannon fires the
cannonballs to the frequency that they hit the target.
Observations:
Explanation:
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8th Grade PSI
Wave Properties
Part 3- Stationary Cannon & Moving Target toward Shooter
 Click Reset Simulation. Select “target motion” moving towards shooter.
Click start simulation. Compare the frequency that the cannon fires the
cannonballs to the frequency that they hit the target.
Observations:
Explanation:
Part 4 - Moving Cannon Away from Target & Stationary Target
 Click Reset Simulation. Select “shooter motion” moving toward target.
Click start simulation. Let the cannon move all the way toward the target
until it stops.
 Then change “shooter motion” to “away from target”.
 Compare the frequency that the cannon fires the cannonballs to the
frequency that they hit the target as the cannon moves away.
Observations:
Explanation:
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8th Grade PSI
Wave Properties
Part 5 – Stationary Cannon & Target Moving Away
 Click Reset Simulation. Select “target motion” moving toward shooter.
Click start simulation. Let the target move all the way toward the shooter
until it stops.
 NOTE: The target does not start moving until it gets hit by at least 1 ball.
 Then change “target motion” to “away from shooter”.
 Compare the frequency that the cannon fires the cannonballs to the
frequency that they hit the target as the target moves away.
Observations:
Explanation:
Questions:
1. Define the Doppler Effect.
2. Make a sketch of the waves a) in front and b) in back of a moving sound source.
Make a comment of the wavelengths and frequencies of both (a) and (b)
compared to each other.
3. Explain where you have witnessed the Doppler Effect in YOUR daily life.
www.njctl.org
8th Grade PSI
Wave Properties