week 8

• Wave


  Vibrations or oscillations traveling in space
• Transverse Wave


  • Particles vibrate perpendicular to the direction of travel
• Longitudinal Wave


  • Particles vibrate parallel to the direction of travel
• Types of Waves

  • Transverse Wave
  • Longitudinal Wave
• Transverse Wave


  • Vibrations of particles are perpendicular to the direction of travel
• Longitudinal Wave


  • Vibrations of particles are parallel to the direction of travel
• Electromagnetic Waves


  Transverse waves without a medium (they can travel through empty space)
• Electromagnetic Waves


  Created as a result of vibrations between an electric field and magnetic field
• Electromagnetic Spectrum


  Name for the range of electromagnetic waves when placed in order of increasing frequency
• Radio Waves


  • Have the longest wavelengths and lowest frequencies of all the electromagnetic waves
  • Can be longer than a football field or as short as a football
  • 3 x 10^11 Hz
• Radio Wave Uses/Applications

  • Global Positioning System (GPS)
  • Radios and Televisions
  • MRI (MAGNETIC RESONACE IMAGING)
  • Communication - Cellular phones
• Microwaves


  • Have the shortest wavelengths and the highest frequency of the radio wave
  • 1 mm - 25 μm can be measured in centimeters
  • 3 x 10^11 - 3 x 10^13 Hz
  • Can penetrate haze, light rain and snow, clouds, and smoke
• Microwave Uses/Applications

  • Microwave Ovens
  • RADAR (Radio Detection and Ranging)
  • Wireless Connection - Wifi networks
• Infrared Light


  • Lies between the visible and microwave portions of the electromagnetic spectrum
  • Has wavelengths that range from red light to violet
  • aka Heat Waves
• Infrared Light Regions


  • Near infrared light
  • Far infrared
• Infrared Light Uses/Applications

  • Thermogram
  • Remote - Control Units
  • Medical and security - Thermal imaging, autoimmune disease treatment, cosmetic radiotherapy and security systems
• Visible Light

  • Only electromagnetic waves we can see
  • Colors of the rainbow
  • When all the waves are seen together, they make white light
  • 750 nm - 400 nm
  • 4 - 7.5 x 10^14 Hz
  • Longest wavelength= red light; Shortest wavelength= violet (purple) light
• Visible Light Uses/Applications

  • Photosynthesis
  • High Speed Data Transmission - Visible Light Communication (VLC) through optical fibers
• Ultraviolet Light


  • Has shorter wavelengths than visible light
  • 400 nm - 1nm
  • 10^15 - 10^17 Hz
• Ultraviolet Light Regions


  • Near UV
  • Extreme UV
  • Far UV
• Ultraviolet Light Types

  • UVA
  • UVB
  • UVC (absorbed by Earth's atmosphere)
• Ultraviolet Light Uses/Applications

  • Sterilization
  • Causes tanning and vitamin D production
  • FORENSICS - Forgery detectors
• 1. X-Rays

  • Have smaller wavelengths and higher energy than ultraviolet waves
  • Can penetrate most matter
  • Tend to act more like a particle than a wave
  • First observed and documented in 1895 by Wilhelm Conrad Roentgen
• 1. X-Ray Uses/Applications

  • Medical Diagnostics and Treatment - Bone Imaging
  • Security and Transportation - Body Scanners and Cargo and Luggage Scanners
  • Industrial Applications - Inspection of Structures
• Gamma Rays


  • Have the smallest wavelengths and the most energy of any other wave in the electromagnetic spectrum
  • Carry the greatest amount of energy and penetrate the most
• Gamma Ray Uses/Applications

  • MEDICINE - Radiotherapy, Kills cancer cells
  • Food Irradiation
  • Nuclear Energy Production