1 / 9

Welcome to PH 103

Welcome to PH 103. Dr. Cecilia Vogel Lecture 1. Class structure. Syllabus You don’t want me to read it to you – so read it on your own! Web page helios.augustana.edu/~cv/103 print lectures before class see in-class work after class announcements, etc Office office hours in Hanson 120

marlaf
Download Presentation

Welcome to PH 103

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Welcome to PH 103 Dr. Cecilia Vogel Lecture 1

  2. Class structure • Syllabus • You don’t want me to read it to you – so read it on your own! • Web page helios.augustana.edu/~cv/103 • print lectures before class • see in-class work after class • announcements, etc • Office • office hours in Hanson 120 • my office is Hanson 121B • Course goals – “facts” are only a small fraction • WebAssign and Quizdom • Clarify: WebAssign homework is 10% of your grade (not pre-flights, which are also on WebAssign) • 5% from pre-flight or in-class work or exam • If I’m grading it, it better be justified! • exception multiple choice

  3. Quizdom Intro Press and hold “menu” to turn on Session ID: 104884 User ID: your student ID (or try a number 1-12 if you are not registered) To input, press the “send” key (double arrow) If this does not work, press “menu” and then use the arrows to find and change session or user ID manually

  4. Light • Electromagnetic wave • oscillating electric and magnetic fields • means the field is sometimes big, sometimes small • E and B are abstract “fields” • -- not moving matter! • not wiggly path! • =purple arrow • along x-axis • =path of light

  5. Wave properties wave moves at speed v wavelength = distance between repeats period = time between repeats frequency = # oscillations per second (speed is c=3X108 m/s only in vacuum) l T f fl=v l

  6. How fast? Frequency of wave how fast is it oscillating? depends on the thing that’s creating the oscillations Speed of wave how fast is it getting from point A to point B? depends on the properties of the thing the wave is traveling through

  7. MEMORIZE EM SPECTRUM • Visible: • Longer: • Shorter: l=400-700nm violet thru red Infrared, microwave, radio UV, X-rays, gamma

  8. Speed of light • Speed of light is c=3X108m/s, only in vacuum • Speed in other materials • is slower than vacuum • index of refraction, n • tells how much slower • in material, v=c/n • n=1 vacuum, n=1.0003 air, • n=1.33 water, n=2.42 diamond

  9. Material and Wavelength • Speed in other materials • is slower than vacuum • If light passes from vacuum to material • frequency is unchanged • but speed changes – what happens to l? • so wavelength decreases when speed decreases • in material, • v=c/n • l=lo/n

More Related