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Wave Motion

  • G3-28 SUSPENDED SLINKY

    G3-28
    Shows longitudinal and transverse traveling waves & standing waves
    Transverse or longitudinal pulses can be created by appropriate motion of your hand at one end of the SLINKY. Using your hand you can also create transverse standing waves and discuss the overtone series. Gently vibrating one end of the spring (either by hand or using the motor) at the appropriate frequency creates longitudinal standing waves.
    FS1

  • G3-29: SUSPENDED SLINKY - PORTABLE

    G3-29
    Show longitudinal and transverse traveling waves and standing waves.
    Transverse or longitudinal pulses can be created by appropriate motion of your hand at one end of the SLINKY. Using your hand you can also create transverse standing waves and discuss the overtone series. Gently vibrating one end of the spring at the appropriate frequency creates longitudinal standing waves.
    OS0

  • G3-31: Spring and Horns

    G3-31
    To audibly illustrate transmission of energy in a mechanical wave
    This long spring has a horn mounted on each end, which amplifies the vibrations from the spring as they pass into the air. Invite a student volunteer to hold each end, and show how energy is transferred through a wave and produces sound at the far end of the spring.

    This demonstration was donated by Prof. William Dorland.

    G3

  • G3-41: WAVE MODELS - PROJECTION

    G3-41
    Demonstrate standing waves, travelling waves, and superposition of waves.
    The wave models are projected and individual members rotated to show particular wave characteristics. Models are: (1) identical waves moving in opposite directions, (2) sum of waves in (1), (3) traveling wave and same with twice the amplitude, (4) identical waves 90 degrees out of phase and their sum, (5) identical waves 180 degrees out of phase.
    G3

  • G3-42: TORSIONAL WAVES

    G3-42
    Demonstrate wave phenomena such as traveling waves, standing waves, and reflection of waves.
    Waves can be started from either end. One end can be clamped to show reflection from free or fixed ends. Both ends can be clamped at the same time or one end can be free and the other fixed to show standing waves.
    G3

  • G3-43 WHIP

    G3-43
    Illustrates transverse wave motion.
    A wave started down the whip increases its velocity as the whip decreases in diameter toward the tip. By the time the wave reaches the tip of the whip, the velocity of the whip motion can become greater than the speed of sound in air. The "cracking" of a whip is believed by many physicists to be a result of the sonic boom thus created.

    Please consider carefully how to appropriately present this device in class if used.
    G3

  • G3-44: WAVE-DRIVEN BUMPER JACK

    G3-44
    Demonstrate that waves transmit energy.
    Waves are sent along the stretched spring from your hand to the other end, which is attached to the handle of a bumper jack. If you send an appropriate frequency of wave, the energy transmitted to the bumper jack will lift the 7 kg mass, demonstrating that the wave is actually transmitting energy.

  • G3-45: RESONANCE OF WIRES

    G3-45
    Show standing waves in heavy wires fixed at one end.
    This uses the mechanical oscillator from G3-46 attached to a trio of wires similar to demonstration G2-11. As the frequency of the oscillator is increased, standing waves appear in each successively shorter wire.
    G3

  • G3-46: STANDING WAVES IN A WIRE LOOP

    G3-46
    Illustrate circular standing waves; to use as a model of stationary states in atoms corresponding to standing waves of electrons in Bohr orbits.
    A wire loop is attached to a mechanical vibrator (the same as used in G3-45). Regulating the frequency of the motor produces different standing wave configurations of the wire loop.
    G3

  • G3-51 ROPE WAVE GENERATOR - FREQUENCY VS. WAVELENGTH

    G3-51
    Shows the relationship between frequency and wavelength for fixed tension cord
    Keeping the tension in the rope fixed (same weight on hook) and raising the frequency creates standing waves with shorter wavelength (more loops).
    FS1

  • G3-52: ROPE WAVE GENERATOR - ROPE TENSION VS WAVELENGTH

    G3-52
    Observe the change in wavelength of a vibrating rope as the tension is varied.
    Set the generator frequency using about 250g to produce 2 loops. Quadrupling the weight increases the wave speed (and thus the wavelength) by about a factor of two, creating one loop, while using about 110 grams creates three loops, two-thirds of the original wavelength. This is Mersenne's second law for stretched strings.
    FS1

  • G3-53 STANDING WAVES IN A STRING

    G3-53
    Demonstrates standing waves on a thin string
    The string is driven by a 60 Hz vibrator with the number of standing wave loops determined by adjusting the tension. Black painted channel is the background for improved visibility.
    OS0, LS1

  • G4-02 RIPPLE TANK

    G4-02
    Illustrates wave phenomena water surface
    This is a large ripple tank which uses an overhead projector as its light source. It is kept on its own cart along with all accessories. Experiments which can be performed with this ripple tank include: Huygens's principle, plane waves and circular waves, single slit diffraction, double slit interference, interference between two sources, reflection and refraction of waves at a boundary, focusing by a concave reflector, focusing by lenses, and the Doppler effect.
    OS7

  • G4-03: RIPPLE TANK - DOPPLER EFFECT

    G4-03
    Show how wave fronts crowd together in front of and spread out behind a moving source.
    The single point source can be moved by rotating the support arm on a lazy susan. Moving the source uniformly in one direction demonstrates the Doppler effect in a clear and understandable way.
    OS7

    g4-03a g4-03b

  • G4-11: SOAP FILM OSCILLATIONS

    G4-11
    Demonstrate standing waves in a two-dimensional medium.

    A large rectangular frame or a circular frame (from M4) are provided for producing soap films using a specially-formulated soap solution. Careful movement allows production of various standing waves.

    Please specify in comments when ordering if you want the circular form, square form, or both.
    OS2, M4

  • G4-12: STANDING WAVES ON A SOAP FILM

    G4-12
    Demonstrate standing waves in a circular membrane.
    A circular wire loop (from M4) holds a soap film which is positioned in front of a loudspeaker (the rectangular box to the left of the soap film). It is illuminated by a bright point source which casts a reflected pattern on the screen as shown in the photograph. A sine-wave oscillator attached to the speaker can be tuned to obtain various standing wave patterns, which are defined by the bright lines in the reflected light. Some standing wave patterns are shown above.
    M4, ME3, LS1

    g4-12a g4-12b

  • G4-13: DRUM HEAD STANDING WAVES

    G4-13
    Demonstrate standing waves in a circular membrane.
    A ripple tank vibrator is used to create standing waves in a circular rubber membrane. Adjusting the frequency changes the standing wave pattern.
    P1, G4

    g4-13a

  • G4-14: SPOUTING BOWL

    G4-14
    Demonstrate resonance in a dramatic way

    Fill the bowl half-way with distilled water only. Make sure your hands are very clean, and wet them slightly before rubbing.

    Rhythmically rubbing the handles of this ornate Chinese bowl sets up an energetic standing wave that will propel the water in the bowl up to a half-meter into the air! Click the link below to see a video of the spouting bowl in action.
    G4

  • G4-21: CHLADNI FIGURES - BOWED

    G4-21
    Show two-dimensional standing waves in a metal plate

    Sand is sprinkled onto a circular or square thin metal plate, which is then stroked along the edge using a violin bow. The sand moves to nodal lines of the standing wave pattern. Stroking at one point while holding your finger at another point to forces a node at that point, if desired, creating a variety of standing wave patterns.

    A nice article describing the Chladni plates at the Whipple Collection wil be found by clicking http://www.hps.cam.ac.uk/whipple/explore/acoustics/ernstchladni/chladniplates/.

    G4

  • G4-22: CHLADNI FIGURES - OSCILLATOR DRIVEN

    G4-22
    Show two-dimensional standing waves in a metal plate
    The Chladni plate is a system for creating and illustrating two-dimensional standing waves in a surface. A variety of flat plates can be mounted on the oscillator (including square, circular, and violin-shaped plates). As the plate vibrates, fine white sand is shaken about and traces out the nodal lines of the vibrations of the plate. The system operates by means of magnetostriction. A thin-walled annealed nickel tube is used to drive various Chladni plates. The nickel tube is threaded into the center of the plate, and inserted through a coil under the plate, which rests on a thick felt surface. An oscillator in the 10-30 kHz frequency range drives a 20-Watt audio amplifier to provide the current creating the magnetic field. The field is biased by a small horseshoe magnet to avoid frequency doubling in the tube. A mirror allows larger groups to view the plate easily.
    FS1