Used to explore the concept of resonance through sympathetic and forced vibrations, and phenomenon of beats. Two matched nickel-plated tuning forks of frequency A (426.6).
Each mounted on top of hollow wooden box open at one end. One fork has a sliding mass on one prong to vary its frequency from the nominal 426.6Hz.
When both forks are sounded a clearly audible “beat” is produced, its rate depending upon the difference in frequency between the forks