1 / 41

Bellringer – 2 mins to hand in

Bellringer – 2 mins to hand in. Describe (in detail) one observation you made yesterday about the properties of light. DO WORK. STOP. Objectives. Fill out answer sheet for homework questions. Finish collecting lab data. Begin to explain the observations you made during the lab.

hilda
Download Presentation

Bellringer – 2 mins to hand in

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. Bellringer – 2 mins to hand in • Describe (in detail) one observation you made yesterday about the properties of light. DO WORK STOP

  2. Objectives • Fill out answer sheet for homework questions. • Finish collecting lab data. • Begin to explain the observations you made during the lab.

  3. Homework • With a number two pencil fill in the answer sheet with your name on it. • Pass it up when you’re done.

  4. Field Trip • Does everyone still want to go to Darien Lake on May 19th? • It will cost around $16.00

  5. What is Light? • Let’s finish collecting our lab data. • Go to your last station.

  6. Light as we know it Take out your “What is light” lab

  7. What properties of light have you discovered? • Emission • Transmission • Reflecting/Scattering • Absorption • Dispersion • Polarization • Diffraction

  8. Emission • A light bulb emits visible light; the energy of the light comes from electrical potential energy supplied to the light bulb.

  9. Transmission • Some forms of matter, such as glass or air, transmit light, which means allowing it to pass through.

  10. Reflecting/Scattering • Light can bounce off matter leading to what we call reflection (when the bouncing is all in the same general direction) or scattering (when the bouncing is more random).

  11. Absorption • When you place your hand near an incandescent light bulb, your hand absorbs some of the light, and this absorbed energy warms your hand. These bananas absorb all colors of light except yellow. Instead yellow is scattered, so the bananas appear yellow!

  12. Bellringer – 2 mins to hand in • Explain why a lime appears green under white light even though white light is made up of all the colors of the wind. DO WORK STOP

  13. Objectives • Review last week’s homework assignment • Be able to use the proper vocabulary to complete last weeks light lab.

  14. Review

  15. Homework • Complete the long answer portion of the June 2012 Regents. • It is due on Friday • Write all the your answers in the correct spot on the answer sheet.

  16. Dispersion • When white light travels through a prism it disperses into a rainbow, showing that white light is made up of all the color we can see.

  17. Polarization • When light passes through a polarizing filter it is only allowed to vibrate in one direction. • Light cannot pass through two polarizing filters that are set 90 degrees from one another.

  18. Diffraction • When a wave encounters an obstacle, or a slit is diffracts and a pattern is produced on a screen.

  19. What is light? • How does light behave like a particle? • How does light behave like a wave?

  20. Is light a particle or a wave?

  21. Is light a particle or a wave? • Wave-Particle Duality says that light exhibits both wave and particle properties. This duality addresses the inability of classical concepts like “particle” and “wave” to fully describe the behavior of light. • This is a central concept in quantum mechanics.

  22. Photons • A photon is one particle of light that obeys the wave-particle duality of light.

  23. Properties of photons • Wave-particle duality • Photons always want to travel at the speed of light in a vacuum: • Every photon as a specific frequency and wavelength that obey: • f is the frequency of the photon (Hz) • Lambda is the wavelength of the photon (m)

  24. Properties of photons • Photons have energy that obey the equation: • h is Planck’s constant: • E is the energy measured in Joules (J) • Note: Not every photon has the same energy

  25. Practice • For a photon that has wavelength of 650nm find its velocity, frequency, energy, and color. • Velocity: • The velocity of a photon is always the same in a vacuum.

  26. Practice cont’d • Frequency of the photon:

  27. Practice Cont’d • Energy of the photon: • Or:

  28. Practice Cont’d • Color of the photon • RED!

  29. More practice • Which has a larger wavelength, red or blue light? • Red • Which has a greater frequency, red or blue light? • Blue • Which has more energy, red of blue light? • Blue

  30. Is there light beyond the Rainbow? • What color light has a wavelength of 200nm?

  31. The Electromagnetic spectrum

  32. Light beyond the rainbow • Gamma Rays, X-Rays, Ultraviolet, Visible, Infrared, Microwaves, and Radio Waves are all part of the electromagnetic spectrum. • They are all electromagnetic rays • We can only detect visible electromagnetic waves with our eyes, but this doesn’t mean the visible waves are a different type of wave than the ones we can’t see.

  33. Chicken Wings • How can chicken wings be used as an analogy for the electromagnetic spectrum? • Spicy Cajun Style • Spicy Glazed • Baked Buffalo • Sesame • Maple • Broiled Barbecued • Inferno • Plain

  34. Radio Waves • TV, FM, AM, Wifi, cell phones • Wavelength – Football field to a baseball • Can you hear radio waves? • “Most people associate the term radio with sound, but radio waves are a form of light with long wavelength-too long for our eyes to see. Radio stations encode sounds as electrical signals and broadcast the signals as radio waves. What we call “a radio” in daily life is an electronic device that receives these radio waves and decodes them to re-create the sounds played at the radio stations.”-The Cosmic Perspective

  35. Microwaves and infrared • Microwaves • Microwave oven, Radar • Wavelength – Lacrosse ball to a small dot • Infrared • People, light bulbs • Wavelength – Cell to bacteria

  36. Visible light and ultraviolet • Visible • The only electromagnetic waves we can see • Wavelength – 780nm to 380nm • Ultraviolet • The cause of sunburn • Wavelength – Virus to a protein

  37. X-Rays • X-Ray machines • Wavelength – Protein to a water molecule • What could you see with X-ray vision? • “The “X-rays” that the doctor or dentist holds up are not a form of light; they are just pieces of film. The images of your bones and teeth are made with the help of a special machine that works somewhat like the flash on an ordinary camera but emits x rays instead of visible light. This machine flashes the x rays instead of visible light, and the x rays that are transmitted through your body are recorded on film. Thus, what you see is the image left by these x rays, not the x rays themselves” -The Cosmic Perspective

  38. Gamma Rays • Radioactive elements • Wavelength – Water molecule to even smaller • Is all radiation dangerous? • Many people associate the word radiation with danger. However, the word radiate simply means “to spread out from a center” (radius-radiation). Radiation is energy being transmitted through space. • High-energy forms of radiation, such as particles from radioactive materials or x rays, are dangerous because they can penetrate body tissues and cause cell damage. Low energy forms of radiation, such as radio waves, are usually harmless.

  39. The full spectrum • How much more do you think we could learn about the universe if we could see the full electromagnetic spectrum?

  40. The full spectrum of telescopes

  41. Homework • One worksheet, front and back • Electromagnetic spectrum practice

More Related