Physics 122 Week 6
Waves
Transverse and Longitudinal Pulses
Most students are familiar with Slinkys, but they may not know how well they can transmit a wave! Use a Slinky as a medium for both transverse and longitudinal wave pulses.
Transverse Wave Model
Show your students how the medium is displaced perpendicularly to the direction of energy propagation in a transverse wave by sliding a sine wave cut out into an array of beads. The cut out has whiteboard material on it so you can illustrate wave properties.
Transverse Waves with Rods
A transverse wave can be visualized by oscillating a rod. By sending two waves towards each other you can also demonstrate superposition. Different “add-ons” can be used to change boundary conditions or aid in creating standing waves.
Longitudinal Wave Pulses
Use the metal spring bars on either end of the suspended slinky to send a longitudinal wave pulse. If the weights on either end are adjusted to be at the same height, you can resonate the opposing spring bar.
Longitudinal Wave Model
Rotate the knob clockwise to begin oscillating the bars to model a longitudinal wave.
**Do not rotate the know the opposite direction**
Particles in a Longitudinal Wave
Magnetic “particles” are rolled towards each other to show how a compression wave propagates through a medium. **Level the track before use**
Sound Production
Tuning Forks and Xylophone Keys
Make sure to use a rubber mallet when striking the tuning forks, but you can drop the Xylophone keys on any surface to produce their tones.
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Disassembled Speaker
This speaker has been disassembled to better allow you to demonstrate how it produces sound waves.
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Doppler Effect
Bloogle Tubes
When you swing these tubes in a circle the turbulent air inside begins to resonate. Increase your frequency to increase the sound's frequency.
Doppler Shift Apparatus
Press the buzzer so that students can hear the resting frequency, then swing it around your head. The buzzer will remain engaged once in motion, and your students will hear the Doppler Effect at its finest!