Group B 1. What is the speed of light while traveling through (a) a vacuum, (b) air at 30 C, and (c) air at 0'C? 2. How much time is required for reflected sunlight to travel from the Moon to Earth if the distance between Earth and the Moon is 3.85 x 10 km? 3. How many minutes are required for a radio signal to travel from Earth to a space station on Mars if the planet Mars is 7.83 x 10 km from Earth? 4. An incident light ray strikes a mirror with an angle of 30 to the surface of the mirror. What is the angle of the reflected ray? 5. The speed of light through a transparent substance is 2.00 x 10 m/s. What is the substance? 6. A monochromatic light source used in a diffraction experiment has a wavelength of 4.60 X 10 m. What is the energy of a photon of this light? 7. In black-and-white photography, a photon energy of about 4.00 X 10- J is needed to bring about the changes in the silver compounds used in the film. Explain why a red light used in a darkroom does not affect the film during developing. 8. The wavelength of light from a monochromatic source is measured to be 6.80 X 10" m. (a) What is the frequency of this light? (b) What color would you observe? 9. How much greater is the energy of a photon of ultraviolet radiation () = 3.00 X 10' m) than the energy of an average photon of sunlight (2 = 5.60 x 10-7 m)? 10. At what rate must electrons in a wire vibrate to emit microwaves with a wavelength of 1.00 mm? 11. What is the speed of light in ice? 12. What is the frequency of a monochromatic light used in a diffraction experiment that has a wavelength of 4.60 x 10 m?For the homework 1217, solve the pbs 1, 2, 3, 4, 5, 8, 11, 12 from your textbook and the two pbs 9 and 10 given below. Pb 9: A ray of light was in water (n = 1.333) enters onto a block of glass (n = 1.530) at a 25.0 angle of incidence and it is refracted at an angle 0 of refraction. a) Determine the angle 0. b) What is the speed of light in the glass? Pb10: A light ray enters in oil-water mixture where the oil is on the top of the water at a 25.0 angle of incidence and it is refracted in the water (n = 1.333) at a 35.0 angle of refraction. What is the index of refraction of the oil