Physics I Honors

Website Notes and Plans For

January 14 to 27, 2009

Chapter 16: The Study of Light.

LNK2LRN™2009/10

The Electromagnetic Spectrum

Daily Plans and Assignments:

1. Thursday(01/14): Intro. to Ch. 16, Light (What is it?),

Illumination, Speed of Light.  HW: Read pages 431-38 and Solve

prob. 53, 54, 55, and 56 on page 453.

2. Friday(01/15): The Wave Nature of Light, Color, Doppler Shift of

Light, and Polarization.  HW: Read pages 439-47, and Solve prob. 58,

59, 60, 62, and 63 on pages 453-4.

3. Tuesday(01/19): Review of the Study of Light. HW: Complete

Review Handout.

4. Wednesday(01/20): Lab on the Illumination of Light. HW: Process

lab data, report due Monday.

5. Thursday(01/21): Post-lab Discussion. HW: Write Lab Report,

due Monday.

6. Friday(01/22): Review I Ch. 16, The Study of Light. HW: Complete

Review Handout.

7. Monday(01/25): Review II Ch. 16, The Study of Light. HW: Complete

Review Handout.

8. Tuesday(01/26): Test on Ch. 16, The Study of Light. HW: Go to

web-site for notes on Ch.17 - Reflection and Mirrors.

Very Important: If you have any questions or miss a class, see

me before school (8:00 - 8:30 AM), during Lunch, or after school.

Best to send an email to rpersin@fau.edu.

 

WEBSITE NOTES: Physics I Honors. Ch. 16 - The Study of Light.

1. Light is electromagnetic radiation that consists of oscillating electric

and magnetic fields with different wavelengths; it is also capable of

stimulating the retina of the eye.

2. Light, moving through a vacuum, a travels in a straight line at a

speed c = 3.0 x 108 m/s, and possesses the properties of both waves

and particles. For light, d = v·t.

3. The intensity, I, of a source of light is measured in candela (cd). The

rate at which light energy is emitted by a source is called luminous flux, P,

and the unit of luminous flux is the lumen (lm). The equation that relates

these two quantities is P = 4πI.

4. The rate at which energy falls on a unit area is illuminance, measured

in lumens/m2, or lux (lx). The equation here is E = P/4πr2.

5. The brightness of light is inversely proportional to the square of the

distance from the light source.

6. Light can have wavelengths between 400 and 700 nanometers, nm.

7. White light is a combination of the spectrum of colors, ROYGBIV,

with each color having a different wavelength.

8. The color of an object is the color of light that it reflects. The frequency

of light is its color.

9. Materials may be characterized as transparent, translucent, or opaque

depending on the amount of light they reflect, transmit, or absorb.

10. Light of different colors can be produced by adding light consisting of

the primary colors (red, green, and blue); white light is a combination of

the spectrum of colors (red, green, and blue), each having a different

wavelength.

11. The subtractive primary colors, cyan, magenta, and yellow are used

in pigments and dyes to produce a wide variety of colors.

12. Colors in soap and oil films are caused by the interference of specific

colors of light reflected from the front and back surfaces of the thin film.

13. Light can be linearly polarized by transmission, reflection, or

scattering; light is polarized if only waves vibrating in a particular plane

are present.

14. When two polarizing filters are used to polarize light, the intensity

of the light coming out of the last filter is dependent on the angle

between the polarizing axes of the two filters, I2 = I1cos2θ.

15. Light waves traveling through a vacuum can be characterized in

terms of wavelength, frequency, and the speed of light. The wave

equation for light, solved for the wavelength in a vacuum is λo = c/f.

16. Light waves are Doppler-shifted based upon the relative speed

along the axis of the observer and the source of light. The equation

for this effect is fobs = f(1± v/c).

17. For Doppler-shifted light, the change in wavelength is given by the

equation Δλ = (λobs - λ) = ± (v/c)λ.

18. And still, we need these steps to solve any problem in Physics:

(i) read the problem and identify the given variables

(ii) determine what you are asked to solve for

(iii) find the correct motion formula to use

(iv) use algebra to isolate the unknown

(v) substitute-in the given information and simplify.

Answers to Homework:

Page 453: 53. 2.0 lx, 54. 3.84x108 m, 55. Use 100 W (1620 lx

               56. 3.0x109 m, 25 km/s, 30 km/s,

               58. 15,000 km or 3/8 distance around the Earth

               59. 7x10-7 m, 60. 3.09x108 m/s

Page 454: 62. (your explanation), 63. 1.95x107 m/s

 

animated open door gifTHE HONORS PHYSICS SEMESTER 1 ARCHIVES
Ch.1: Physics Intro. Ch.2&3: Linear Motion. Ch.4&5: Forces.
Ch.6: 2-Dim Motion. Ch.7: Gravitation. Ch.8: Rotary Motion.
Ch.9: Momentum. Ch.10&11: Work&Energy. Ch.12: Thermal Energy.
Ch.13: States of Matter. Semester Review. Ch.14&15: Waves&Sound.
Ch.16: Study of Light. Ch.17&18: Mirrors & Lenses. Ch.19: Light Interference.
 

CLICK ON THE LINKS BELOW TO LEARN MORE ABOUT THIS WEEK'S TOPICS

LIGHT (WHAT IS IT?)

VISIBLE SPECTRUM

 

SPEED OF LIGHT

 

COLORS OF LIGHT

POLARIZATION OF LIGHT

DOPPLER SHIFT

MAY THE NET FORCE BE WITH YOU!

Black History Month

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And Always Remember...

"From  Newtonian Mechanics,

Through Quantum Theory,  

Without  Physics,  

Life Would Be Dreary."

LINK TO YOUR TEXTBOOK.

  ENGINEERS EDGE

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