Oscillations and Waves Area

Oscillations

Topic 20 demos

Yellow chalk-line bob swinging on a short string from a horizontal rod on a clamp stand, with motion blur showing a wide arc in front of a chalkboard

Simple Pendulum

A simple pendulum with easily adjustable string length demonstrates how period depends on length:. The bright yellow bob is visible even in the largest lecture halls.

Ring stand with horizontal rod supporting multiple pendulums of different lengths and bob types (cork cylinder, golf ball, plumb bob, green ball) on white and red strings

Pendulum Experiments

A do-it-yourself pendulum kit for investigating period dependence on length , independence from mass, and the small-angle approximation. Assemble pendulums to match clicker questions or run in-class experiments.

Two pendulums hanging from a horizontal rod between two tall bench clamp stands, with black nylon string looped over ring clamp hooks and brass mass hangers at the bottom; a blue PASCO mass set sits on the bench

Twin Pendulums

Demonstrates that the period of a simple pendulum is independent of mass. Two pendulums of equal length but different masses remain synchronized over many swings, directly testing and challenging the …

Wave Motion

Topic 30 demos

Lecture hall viewed from the back rows, with white plastic tubing hanging from the upper balcony railing and curving down toward the front of the room

Transverse Waves

Demonstrates transverse wave pulses, fixed-end reflection with phase inversion, constructive and destructive interference, and standing wave formation using a long plastic tube stretched across the lecture hall.

Close-up of the upper portion of the torsional wave machine, showing horizontal rods with white end-balls attached to a vertical wire, mounted to a catwalk bracket above the lecture hall

Torsional Wave Machine

Demonstrates torsional wave propagation along a vertical cable with perpendicular rods. Students observe pulse propagation, reflection with phase reversal at a fixed boundary, and superposition of incident and reflected waves.

Pendulum wave apparatus photographed mid-swing from below, showing steel balls on bifilar suspension at progressively different lengths

Pendulum Waves

An array of pendulums with harmonically related lengths cycles through striking patterns of coherence and apparent chaos over a 54-second period. Demonstrates beat phenomena, phase relationships, and the superposition of …

Acoustics

Topic 12 demos

Anatomical ear model on white base showing cross-sectioned outer ear, ear canal, and internal structures, with two removable bone sections placed in front

Ear Model

Anatomical model of the human ear with removable sections to show the mechanical chain from sound collection (outer ear) through impedance matching and amplification (middle ear) to frequency analysis (cochlea). …

Two signal generators, a Behringer Eurolive B205D powered monitor speaker, an Agilent oscilloscope, and a microphone on a lab bench

Range of Hearing

Demonstrates the range of human hearing by sweeping from 20 kHz downward. Students raise their hands when they hear the tone, vividly showing that high-frequency hearing declines with age — …

Galton's whistle mounted on a Leybold stand with rubber hose for compressed air supply

Galton's Whistle

Galton's whistle produces very high-frequency sound at or above the limit of human hearing. Students discover that sound exists beyond audible perception -- younger audience members typically hear it while …

Instruments

Topic 27 demos

Violin with bow resting on gray surface

Violin

A violin demonstrates standing waves on vibrating strings. Students observe how tension, length, and linear mass density determine fundamental frequency and overtones when strings are bowed or plucked.

Three wooden organ pipes of increasing length lying on a green surface; the smallest has a removable stop, the middle one has a thin wood membrane panel, and the longest has a glass window

Special Organ Pipes

Three specialized wooden organ pipes designed to illustrate open vs. closed pipe resonance and visualize standing wave nodes using sand and cork dust. **Note: All three pipes are currently non-functional …

Four corrugated plastic tubes with flared ends in orange, red-white striped, pink-green striped, and light blue, laid out on a gray surface

Whirling Tubes

Demonstrates harmonics of an open pipe. Spinning a corrugated tube faster excites successively higher harmonics, producing discrete pitch jumps rather than a continuous glissando — a vivid illustration of standing …

Sound Reproduction

Topic 3 demos

Audio cart with two stacked Agilent signal generators on left, microphone on stand, Behringer Eurolive speaker in center, and widescreen oscilloscope displaying sine wave on right

Sound Cart

A self-contained audio cart with signal generators, oscilloscope, microphone, and speaker for demonstrating waveforms, frequency, amplitude, harmonics, beat frequencies, and wave superposition. The oscilloscope can be projected via VGA for …

Side view of paper speaker: white picnic plate supported on foam core base with copper wire coil wound around small NdFeB disc magnets beneath the plate center, BNC connector at left

Paper Speaker

A DIY speaker built from a paper plate, magnets, and copper wire shows how alternating current through a voice coil drives mechanical vibrations. At low frequencies (12--15 Hz) the plate …

Assembled half of cutaway speaker showing cone, corrugated spider, voice coil region, and black metal frame

Cutaway Speaker

A speaker cut in half reveals the internal construction of a dynamic loudspeaker. Students see how the cone, suspension, voice coil, and magnet assembly work together to convert electrical signals …