CRITICAL INFO:
- Waves transfer energy through a medium
- Velocity of a wave is CONSTANT
- Transverse Wave = movement of wave is perpendicular to velocity (jump rope)
- Longitudinal Wave = movement of wave is parallel to velocity (like Dominos)
- Standing Wave = stationary wave -- remain in constant position
- No net energy
- Only occur at certain frequencies (shakes/second) -- Harmonics
- Harmonics = Frequency at which standing wave occurs
- Wind Instruments: only odd harmonics occur because sound must escape
- Even harmonics do not exist
- Equation: Velocity = (Wavelength)(Frequency)
- REMEMBER: wind instruments go by 1/4
** Guitar strings are an example of transverse waves
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In the tuning fork lab, we were able to record the note that each tuning fork emitted, and from there derive several things leading up to defining what exact note it was. Though the Vernier graph that was produced from the recording, we were able to see an FFT graph similar to the one in the picture on the side. By looking at the graph, we were able to analyze the graph and see what harmonic we actually hear (amplitude).
Plugging in that frequency to the Wolfram Alpha website, we were able to pinpoint what exact note and key the sound was.
** Note: the graph shows that the fundamental frequency is 250 Hz because the that is the lowest in which a standing wave occurs for THAT SPECIFIC MATERIAL. The following numbers are multiples of 250, serving as the 2nd, 3rd, 4th, etc. harmonics.
