Doppler Effect Whirling Ball - Physics Demonstrations - Doppler Effect Whirling Ball | Physics Undergraduate Labs

Before each use, verify that the string is securely clipped to the netting. A failed connection during whirling could send the ball flying into the audience or equipment. Test by pulling firmly on the string before activating the buzzer.

Purpose

Students directly hear the Doppler frequency shift from a buzzing ball whirled overhead. The pitch rises as the ball approaches and falls as it recedes, giving intuitive access to how relative motion between source and observer affects perceived frequency.

Orange foam ball wrapped in blue netting with attached clip and white string coiled on green surface, containing internal buzzer for Doppler effect demonstration

Figure 1: The whirling ball apparatus consists of a foam ball with internal buzzer secured by netting, attached to a string for circular motion demonstrations of the Doppler effect.

Foam Ball with Internal Buzzer

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Safety Warnings

Warning: Secure Connection Critical

Purpose