Physics 410

1. Physics 410 Light and Color Chapter 14

2. Doppler Effect • the change in wavelength due to motion of the source or observer • "Wheeeeeeeeeeee…….Oooooooooooooo” • Examples: • Water, Sound, and Light

3. Wavelength Source at Rest

4. What happens when the source in in motion? • Movie #1 Java

5. Long Wavelength Low Frequency Low Pitch Ooooooo!!! Short Wavelength High Frequency High Pitch Weeeeeeeee!!! As a team, describe what happens to the wavelength, frequency, and pitch both in front of and behind a moving sound source. Source in Motion

6. Doppler Effect • Examples: • moving cars and trains • Sound • Movie #2 • moving buzzer in a nerf ball (in class)

7. R O Y G B I V The Electromagnetic Spectrum • . Radio Waves - communication Microwaves - used to cook Infrared - felt as warmth Visible Light - detected by your eyes Ultraviolet - causes sunburns X-rays - penetrates tissue Gamma Rays - most energetic Mnemonic? Raging Martians Invade Roy G. Biv Using X-rays and Gamma Rays

8. The Electromagnetic Spectrum Radio Waves Microwaves Infrared Visible Light Ultraviolet X-rays Gamma Rays Which form of light has the …longest wavelength? …highest frequency? …highest energy? …fastest speed?

9. Optical IllusionsAnimation

31. Physics 410 Light and Color Chapter 14

32. How to Study • Read the chapters in the syllabus and focus on the topics covered in class. • Chapter 13 - Waves and Sound • Chapter 14 - Light and Color • Chapter 18 - Atomic Models • Chapter 15 - Reflection and Refraction • Review your notes and class exercises. • Use the access code on the inside cover you’re your book to gain access to example questions and flashcards online. • http://www.physicsplace.com/

33. FlashlightsGet them all to work.Disassemble-Reassemble Race

35. Things that create a Spectrum • Prism • Raindrops • CD’s • Diffraction Grating

36. Incandescence • Hot, dense solids produce a continuous spectrum. • Demo - an incandescent light bulb and diffraction gratings Continuous Spectrum

37. Ziplock BagHome for Diffraction Grating

38. Creating a Spectroscope • Roll up and tape black paper to form a tube. • Cover end of the tube with foil. • Use a pencil to make a hole in the foil. • Temporarily tape the diffraction grating over the other end of the tube. • Observe several light sources.

40. Emission Spectra • Hot gas produces a bright line emission spectrum. • Demo - hot hydrogen gas and diffraction gratings Emission Spectrum

41. Hydrogen Helium Oxygen Carbon Every element can be “fingerprinted” by it spectra.

42. Structure of the Atom • Proton • Neutron • Electron • Energy Levels

43. Excitation • When an electron is raised to a higher energy level, the atom is said to be excited.

44. Emission • When the electron returns to a lower energy level, energy is released in the form of light.

45. Different transitions from high levels to low levels result in different colors of light.

46. The color of light emitted by a hot object changes with its temperature. • Glowing object colors: • Reddish coolest glowing object • Orange-ish • Yellowish • White • Bluish  hottest glowing object

48. Object Names • Incandescent Light Bulb • Bright Plate #1 __________ • Bright Plate #2 __________ • Bright Plate #3 __________

50. Object Names • Filter #1 __________ • Filter #2 __________ • Filter #3 __________ • Filter #4 __________