Waves appear throughout physics. In these explorations we are particularly concerned with exploring models of sound waves. We use simple tools in our studies: slinkies, coiled phonecords, and student bodies.
We'll begin by exploring the types of waves which can travel down a coiled spring. There may be more than you think!
Slinky in hand snack: Stretch a slinky between two people and explore the different types of waves you can send.
Next its time to get quantitative in our explorations. We'll study the relatively simple side to side oscillations of a coiled phonecord.
Slow Waves on a Phonecord
Whenever I use these coiled phonecords I think about telephone company research labs that spent millions of research dollars finding a cord that was resistant to abuse by children! This makes them perfect for classroom use.
Next we'll explore resonances in a coiled phonecord of fixed length.
The phonecords used in the last activity model sound waves in tubes closed at both ends, to model waves in tubes open at one end and closed at the other we can hold one end of a slinky and allow the other end to dangle.
To obtain a full body-on experience with wave motion, students can do a dance in which they act out the motions of air parcels participating in a sound wave in a tube.
Dance of the Sound Waves
We can also explore standing waves by hanging a slinky by verical strings from a thicker cord.
With all of these explorations behind us I know I am confused about waves on a much higher level than before.
Return to Summer Institute
Scientific Explorations with Paul Doherty
25 May 2000