Physics 2: Harmonic Motion
This course examines periodic motion of all kinds, from bouncing springs to vibrating strings to resonating pipes. The underlying similarities in the cause and analysis of these motions is addressed, and students examine a variety of behaviors including reflection, refraction, diffraction, and interference. This information is applied to a wide variety of situations including the behavior of musical instruments, acoustics, and earthquake and water waves.
SAMPLE ASSIGNMENT:
Produce a musical instrument capable of playing a pentatonic scale:
C 261 Hz
D 294 Hz
E 330 Hz
G 392 Hz A 440 Hz
You may make the same frequencies in a different octave (double or halve these frequencies).
Each instrument must be accompanied by either an explanatory poster or lab report explaining your initial plans, calculations, process, and process analysis.
Available Materials
Wood (2×4s, plywood)
Wire of different gauges
String
PVC piping of various lengths and diameters
Copper pipes
Pipecutters (PVC and copper)
Metal hooks/loops
Rubber bands
Duct tape
Screws/nails/etc
Tools (drill, saw, hammer, screwdriver, tape measure, rulers, etc.)
You may make the same frequencies in a different octave (double or halve these frequencies).
Each instrument must be accompanied by either an explanatory poster or lab report explaining your initial plans, calculations, process, and process analysis.
Available Materials
Wood (2×4s, plywood)
Wire of different gauges
String
PVC piping of various lengths and diameters
Copper pipes
Pipecutters (PVC and copper)
Metal hooks/loops
Rubber bands
Duct tape
Screws/nails/etc
Tools (drill, saw, hammer, screwdriver, tape measure, rulers, etc.)
Copper Pipe Glockenspiel
"My instrument was influenced by a glockenspiel. The variable I changed in this instrument was the length (in order to change the pitch). I cut the pipe to different sizes to create different pitches. The pitch is directly related to the length of the pipe. If a length is determined for one note, the lengths for other notes can be determined using the following formula: Length of Pipe = Length of Original (Scale Ratio) 1/2. I was surprised to learn that there are specific ratios that can be used to make other notes, given a known note and length. The project was successful in that the notes are very close to the target frequencies, and no tuning is required. I could improve the design by adding additional notes and adjusting the frequencies more carefully. The sound could be improved by mounting the pipes at the exact position of the nodes, so there is less impact from the rubber bands."
— Emily '19, WPI '23
— Emily '19, WPI '23
CSW—a gender-inclusive day and boarding school for grades 9-12—is a national leader in progressive education. We live out our values of inquiry-based learning, student agency, and embracing diverse perspectives in every aspect of our student experience. Young people come to CSW to learn how to learn and then put what they learn into action—essential skills they carry into their futures as doers, makers, innovators, leaders, and exceptional humans who do meaningful work in the world.