EELE 217 Lecture 4
Topics for today:
-
Start out with a short in-class quiz.
- Energy and Power discussion (cont.)
- Energy units: joules, calories, kilowatt-hours, therms.
- Power units: watts, horsepower.
- Wave motion in the air.
- Sound waves can be viewed as localized particle displacement, or as a pressure disturbance.
- Sound waves in air are longitudinal: the particle motion is forward-backward in the direction the wave is propagation.
- Sound waves have a speed, and a physical repetition period and wavelength.
Speed of sound c = frequency times wavelength. - Sound waves are susceptible to propagation, reflection, absorption, refraction, and diffraction.
Topics for the next lecture:
- Read chapters 6 and 8 from the textbook.
- Interference and beating.
- Harmonics and spectrum.
- Sound levels and the decibel.