Doppler Effect Kit

A simple Doppler effect kit — swing a buzzing source on a string and hear the pitch rise as it nears and fall as it moves away, exactly like a passing siren.

How it works

1. Switch on the buzzer and swing it on the string
2. As it moves toward you the pitch sounds higher
3. As it moves away the pitch sounds lower

What students learn

• Explain the Doppler effect
• Relate apparent pitch to the source's motion
• Connect it to sirens and passing vehicles

Try these experiments

1. Swing the buzzer in a circle and listen
2. Compare pitch approaching vs receding
3. Discuss real-life Doppler examples

Curriculum fit

In the box

• Buzzer with a long string
• Battery cells and plastic cell holder
• Demonstration kit

Pairs well with

Tuning Fork SmallSAW-104Organ Pipe ModelSAW-103