1 Vibrations: Overview
Vibrations cause sound. Strike a tuning fork with something soft (your knee, a rubber mallet) and you hear a tone. Touch the tines of the tuning fork to the hairs on your arm and you feel a soft tickling sensation. Touch a stereo speaker while it’s producing sound, and you feel the vibrations.
When something vibrates, it disturbs the material that surrounds it- usually air. When vibrations arrive at a detector (like your ear or a microphone), the detector turns those vibrations into electrical signals that can be interpreted or recorded. Devices like human ears and microphones that turn vibrations into electrical signals which can be recorded and/or interpreted are called transducers.
This part of the book focuses on vibrations in detail.
Vibrations: Learning Objectives
- Describe vibrations using basic terminology: period, frequency, amplitude, fundamental frequency, spectral content
- Describe the relationship between period and frequency and apply it to problems
- Recognize that complicated vibrations are combinations of simpler vibrations all happening simultaneously
- Compare and contrast simple harmonic motion (SHM), complex vibrations, noise and transients
- Interpret time domain graphs of vibrations
- Interpret frequency domain graphs of vibrations