phy 108 questions 9

Homework problems: Chapters 15-16

  • Suppose that water waves have a wavelength of 2.4 m and a period of 0.5 seconds. What’s the velocity of these water waves?
  • A sound wave has a velocity of 334 m/s and a frequency of 400 Hz. What’s the wavelength of the sound? What type of waves are sound waves?
  • Two waves propagate from different directions on the same rope. Suppose they have the same amplitude 0.2 m. What’s the possible maximum and minimum fluctuation of the rope, respectively?
  • The tension force on a string is 80 N. The mass of the string is 0.1 kg and the length is 0.5 m. What will be speed of waves produced on the string?
  • An orange light has a frequency of 6×1014 Hz. What’s its wavelength? What type of waves are light waves?
  • Please list all known electromagnetic waves in order of frequency from highest to lowest.
  • What is electromagnetic induction and what are its applications?

Homework problems: Chapter 17

  • A laser beam reaches surface of a glass block with an incident angle of 45⁰.
    1) Please draw a schematic diagram to show reflection ray and refraction ray.
    2) If glass has an index of refraction of 1.5, what’s the speed of light in glass.
  • A converging lens has a focus length of 10 cm. A pencil stands on its optic axis with a distance of 15 cm from the lens.
    a) Please draw three principal rays to find the image of the pencil;
    b) What’s the image distance?
    c) Is it magnified? Is the image inverted?
  • A concave mirror has a focal length of 10 cm. Please draw two principal rays to find the image of a pencil standing 15 cm away from it.