6.2 Electromagnetic Waves

• What are electromagnetic waves defined as?

  Transverse waves transferring energy
• What is a common property of all electromagnetic waves?

  They can travel through a vacuum
• How many types of electromagnetic waves are there?

  Seven types
• How is the electromagnetic spectrum arranged?

  By wavelengths or frequencies

  
• What part of the electromagnetic spectrum is visible light?

  A small part of a larger spectrum
• What happens to radiation with higher frequency?

  It has higher energy and is more harmful
• What is the percentage of the electromagnetic spectrum that visible light occupies?

  0.0035%
• Which colors correspond to the longest and shortest wavelengths?

  Red has the longest, violet the shortest
• What are the colors of the visible spectrum in order?

  • Red
  • Orange
  • Yellow
  • Green
  • Blue
  • Indigo
  • Violet
• What mnemonic can help remember the colors of the visible spectrum?

  “Roy G. Biv” or “Richard Of York Gave Battle In Vain”
• How does the electromagnetic spectrum order relate to wavelength?

  It decreases from longest to shortest wavelength

  
• What type of radiation do microwaves transfer energy to?

  Water molecules
• What do all hot objects emit?

  Infrared radiation
• What types of EM radiation does the Sun emit?

  Visible light, infrared, ultraviolet

  
• What happens to EM waves when they move from one medium to another?

  They can be transmitted, absorbed, reflected, refracted
• What determines how EM waves interact with materials?

  The wavelength of the waves and the material
• How does glass interact with visible light?

  It transmits and refracts visible light
• What happens to EM waves in different substances?

  They slow down and may refract
• What changes during refraction of light?

  Speed and wavelength change
• What does the normal line represent in refraction diagrams?

  A line perpendicular to the surface
• How does light behave when passing from less dense to more dense media?

  It bends towards the normal
• What happens to light when it passes along the normal?

  It does not bend at all
• What is the relationship between frequency and color in light?

  Different frequencies correspond to different colors

  
• What is the aim of the infrared radiation experiment?

  To investigate how surface color affects absorption
• What is the independent variable in the infrared radiation experiment?

  Color of the surface
• What is the dependent variable in the infrared radiation experiment?

  Temperature of the water
• What should be controlled in the infrared radiation experiment?

  Identical flasks and same water amounts
• What is the expected result of the infrared radiation experiment?

  Heat loss varies by surface color
• What are systematic errors in the infrared radiation experiment?

  Errors due to inconsistent starting temperatures
• What are random errors in the infrared radiation experiment?

  Errors due to measurement inaccuracies
• What safety considerations should be taken in the experiment?

  Keep water away from electrical equipment
• What should be done if burns occur during the experiment?

  Run under cold water for 5 minutes
• What is the resolution of the thermometer used in the experiment?

  1°C
• What is the resolution of the stopwatch used in the experiment?

  0.01 s
• What is the relationship between temperature and thermal radiation emitted?

  Hotter objects emit more thermal radiation
• What factors affect the intensity of emitted radiation?

  Temperature and surface area of the body
• What is the expected outcome when plotting temperature against time?

  Curves of best fit will show heat loss
• What should be done to ensure accurate readings in the experiment?

  Use a data logger for precise measurements
• What is the effect of surface color on heat loss?

  Different colors affect the rate of heat loss
• What is the significance of repeated readings in the experiment?

  To minimize random errors and improve accuracy