Waves, sound, and light

We observe things move in two fundamentally different ways. A car moving from one place to the next is well described by concepts of speed and position. The vibration of a guitar string, however, has additional complexity that needs additional physical concepts to describe. In the physics of waves, sound, and light, we will often use the term frequency to describe how quickly the vibration repeats. Read the text aloud What do a cell phone tower, radio, colors on a TV screen, and ripples in a pond have in common?
A guitar playing the note “A” oscillates back and forth at a frequency of 440 vibrations per second. In an acoustic guitar, the string vibrates the guitar top, which sets off a traveling oscillation in air, called a sound wave. Colors, cellphones, radio, and the ripples on a pond are other examples of waves and their applications. Read the text aloud
Musical notes are frequencies of soundSound waves carry both energy and information. Music is a form of information. When pressed, the keys of a piano create different frequencies of sound waves. A song is physically a complex “sonic image” created by your brain from patterns of frequency and loudness received by your ear. Guitars and pianos use vibrating strings of different length and tension to make different frequencies. Trumpets and pipe organs use vibrating columns of air. Read the text aloud
You see everything around you because it either emits or reflects light that then travels to your eyes. This is the physics of light and the technology of optics. Light travels through air, water, glass, or even empty space. Fundamentally, light is a wave in the electromagnetic field everywhere around us. Light ordinarily travels in straight lines, but it can be deflected by mirrors or lenses (such as in a telescope) to form images. Show Optical fibers
How does the light from a distant galaxy make it to your computer screen?
Show Photonic computers?

A wave is a traveling oscillation that carries information. What information does each of the following type of wave convey?

  1. water waves
  2. sound waves
  3. light waves
  4. a vibrating guitar string

Light is an electromagnetic wave. Which of the following are also types of electromagnetic waves?

  1. tidal waves
  2. gamma rays
  3. radio waves
  4. sound waves
  1. I and II only
  2. II and III only
  3. II, III, and IV only
  4. I, II, III, and IV

Previous Page Next Page7