Resonance Apparatus – Speed of Sound in Air

Investigate resonance, wavelength, frequency and the speed of sound in air using this classroom resonance apparatus. By adjusting the length of an air column above water and holding a vibrating tuning fork over the opening, students can identify resonant positions and explore the relationship between air-column length and sound frequency.

Key Features

• Demonstrates resonance in an air column above water
• Supports investigations into standing waves, wavelength and frequency
• Uses a tuning fork of known frequency to excite the air column
• Allows measurement of the resonant air-column length
• Suitable for secondary school physics and acoustics experiments

Classroom Applications

• Investigate resonance in a tube closed at one end by water
• Explore the quarter-wavelength approximation for the first resonance
• Estimate the speed of sound using v = f × λ
• Compare measured values and discuss experimental uncertainty, including end correction

How It Works

Hold a vibrating tuning fork just above the opening of the tube, without touching it. Adjust the water level to vary the length of the air column and listen for an increase in sound intensity at resonance. For the lowest resonant mode, the air-column length is approximately one-quarter of the wavelength; more accurate results account for the tube's open-end correction.

Additional Equipment

A suitable tuning fork of known frequency is required for the investigation. Please confirm the supplied contents before ordering; the existing product information does not establish whether a tuning fork is included.