Ch. 27_ Concept Development Packet_KEY

NameClass Date Concept-Development Practice Page Light 27-1 1. The Danish astronomer Olaus Roemer made careful measurements of the period of a moon about the planet Jupiter. How this data enabled a calculation of the speed of light is described in your textbook on pages 534 and 535. a. What is the diameter, in kilometers, of Earth’s orbit around the sun? 300,000,000 km b. How much time is required for light to travel across the diameter of the orbit? 1000 s c. How do these two quantities determine the speed of light? Speed = distance/time = (300,000,000 km)/(1000 s) = 300,000 km/s 2. Study Figure 27.4 on page 536 in your textbook and answer the following: a. Which have longer wavelengths, radio waves or light waves? Radio waves b. Which have longer wavelengths, light waves or gamma rays? Light waves c. Which have higher frequencies, ultraviolet or infrared waves? Ultraviolet waves © Pearson Education, Inc., or its affiliate(s). All rights reserved. d. Which have higher frequencies, ultraviolet waves or gamma rays? Gamma rays 3. Carefully study Section 27.4 in your textbook and answer the following: a. Exactly what do vibrating electrons emit? Energy that is carried in an electromagnetic wave b. When ultraviolet light shines on glass, what does it do to electrons in the glass structure? Ultraviolet light causes electrons to vibrate in resonance with the ultraviolet light. c. When energetic electrons in the glass structure vibrate against neighboring atoms, what happens to the energy of vibration? The energy of vibration becomes heat. d. What happens to the energy of a vibrating electron that does not collide with neighboring atoms? The energy is emitted as light. CONCEPTUAL PHYSICS Chapter 27 Light 121 Both cast shadows. .e. Earth’s shadow falls on the moon.75c in water. 0. b. Inc.41c in a diamond. Draw the moon at a position for a lunar eclipse. and diamond? The speed of light is 0. Which range of light frequencies. Which range of light frequencies. In a lunar eclipse. or its affiliate(s). How is the speed of light in glass affected by the succession of time delays that accompany the absorption and re-emission of light from atom to atom in the glass? The average speed of light is less in glass than in air. 4. This sketch also shows the sun and Earth. and 0. h. Earth’s shadow falls on the moon. All rights reserved. a. In what part of the shadow could an ant see part of the lamp? Penumbra CONCEPTUAL PHYSICS 122 Chapter 27 Light © Pearson Education.67c in glass. glass. The sun normally shines on both Earth and the moon. at other times. How does the speed of light compare in water. visible or ultraviolet.. the moon’s shadow falls on Earth. is absorbed in glass? Ultraviolet f. is transmitted through glass? Visible g. The sketch shows the sun and Earth. Shade the umbra darker than the penumbra. The diagram shows the limits of light rays when a large lamp makes a shadow of a small object on a screen. visible or ultraviolet. 5. In a solar eclipse. Draw the moon at a position for a solar eclipse. Sometimes the moon’s shadow falls on Earth and. a. Inc. Although in practice the polarizing filters are one atop the other. All rights reserved.Name Class Date Concept-Development Practice Page Polarization The amplitude of a light wave has magnitude and direction and can be represented by a vector. From left to right: (a) Non-polarized light is represented by its horizontal and vertical components. we show them spread out side by side below. Consider the transmission of light through a pair of polarizing filters with polarization axes at 45° to each other. (e) which is transmitted. The vibrations of non-polarized light are equal in all directions. To the left. There are as many vertical components as horizontal components. the single vector represents vertically polarized light.. 2. b. (b) These components strike filter A. In the sketch below. and (d) falls upon filter B. Light is transmitted by a pair of polarizing filters when their axes are (aligned) (crossed at right angles) and light is blocked when their axes are (aligned) (crossed at right angles). non-polarized light from a flashlight strikes a pair of polarizing filters. but it has a component that is — component t. CONCEPTUAL PHYSICS Chapter 27 Light 123 . or its affiliate(s). This vertical component is not aligned with the polarization axis of filter B. compared to the amount that gets through Filter A is (more) (less) (the same). a. The amount of light that gets through Filter B. Transmitted light is polarized in a direction (the same as) (different than) the polarization axis of the filter. b. Polarized light vibrates in a single direction and is represented by a single vector. The component perpendicular to t that falls on Filter B is (also transmitted) (absorbed). 27-2 1. The pair of perpendicular vectors to the right represents non-polarized light. © Pearson Education. (c) The vertical component is transmitted. Below are a pair of polarizing filters with polarization axes at 30° to each other. CONCEPTUAL PHYSICS 124 Chapter 27 Light © Pearson Education. A novel use of polarization is shown below. 5.. then from inside their homes. Figure 27. Carefully draw vectors and appropriate components (as in Question 2) to show the vector that emerges at (e). All rights reserved. Inc. Use vector diagrams to complete steps (b) through (g) below to show how light gets through the three-polarizing filter system. The occupants can see outside views normally out their windows.17 in your textbook shows the smile of Ludmila Hewitt emerging through three polarizing filters. How do the polarized side windows in these next-toeach-other houses provide privacy for the occupants? (Who can see what?) . or its affiliate(s).3. they cannot see through the side windows of their neighbors. but if the side windows are polarized with axes at 90 degrees to each other. 4. The amount of light that gets through the polarizing filters at 30° compared to the amount that gets though the 45° polarizing filters is (less) (more) (the same).