1. Electromagnetic Waves 5.1 The Electromagnetic Spectrum

2. Learning objectives Be able to name the regions of the EM spectrum Be able to name the regions of the EM spectrum Be able to describe the properties of a wave Be able to describe the properties of a wave Be able to use the ‘wave equation’ Be able to use the ‘wave equation’

3. What do waves do?

8. Waves carry energy from one place to another. There are 2 main types of wave you need to know about: Transverse Waves e.g. light waves Longitudinal Waves e.g. sound waves Types of waves

9. What type of energy is the wave transferring? In which direction is the energy moving? In which direction is each part of the spring moving? kinetic Longitudinal waves

10. What type of energy is the wave transferring? In which direction is the energy moving? In which direction is each part of the rope moving? kinetic Transverse waves

11. Wave properties

12. Wavelength (Lambda, λ) Wavelength (Lambda, λ) Distance from the peak of one wave to the peak of next wave Distance from the peak of one wave to the peak of next wave Energy of wave depends on wavelength Energy of wave depends on wavelength Radio waves = 1000m Radio waves = 1000m X-rays = 0.000000000001m X-rays = 0.000000000001m Frequency (Hertz, Hz) Number of complete waves passing one point in a second 1 Hz = 1 wave/second 1 kilohertz = 1000 Hz 1 megahertz = 1 million Hz

13. Wave speed All EM waves = 300 million m/s (vacuum) All EM waves = 300 million m/s (vacuum) Speed of light Speed of light Speed (m/s) = frequency (Hz) x wavelength (m) Speed Wave length Frequency

14. Electromagnetic spectrum Electrical and magnetic disturbances that transfer energy Electrical and magnetic disturbances that transfer energy All travel at speed of light All travel at speed of light Energy transferred – wavelength Energy transferred – wavelength Put into groups according to wavelength Put into groups according to wavelength Different waves lengths = different effects Different waves lengths = different effects

15. Radio Micro Infra- Red Visible Light Light Ultra- Violet X rays Gamma Wavelength ( ) increases High frequency Short wavelength High energy Most penetrating Low frequency Long wavelength Low energy Least penetrating The EM spectrum

16. Learning outcomes Properties of a wave: Properties of a wave: Wavelength Wavelength Amplitude Amplitude Frequency Frequency Using the ‘wave equation’ Using the ‘wave equation’ The EM spectrum The EM spectrum Different regions depending on properties Different regions depending on properties R-M-I-V-U-X-G R-M-I-V-U-X-G