PURPOSE: To show damped oscillations.
DESCRIPTION: A tuning fork is pinched by fingers to force a damping effect on the oscillations. When the fingers pinch low near the base of the fork the oscillations are under-damped. When the fingers pinch high near the top of the fork the oscillations are over-damped. A microphone in the resonant sound box of the tuning fork picks up the oscillations and inputs the signal to the oscilloscope. A digital storage oscilloscope with a long time base of 400msec is used in single sweep mode to display the oscillations. The trace is frozen on the scope using the run/stop button. The stored trace from the oscilloscope is displayed to the class.
EQUIPMENT: Tuning fork, oscilloscope, microphone as photographed.
SETUP NOTES: See file labed "Damped Oscillations" in demonstration instructions file cabinet
Updated by JZ in 1/27/2006