2. LEFT CLICK OR PRESS SPACE BAR TO ADVANCE, PRESS P BUTTON TO GO BACK, PRESS ESC BUTTON TO END LEFT CLICK OR PRESS SPACE BAR TO ADVANCE, PRESS P BUTTON TO GO BACK, PRESS ESC BUTTON TO END COMPUTER PRESENTATIONS FOR KS3 SCIENCE - PHYSICS ©2003, STEVE PARKER COMPUTER PRESENTATIONS FOR KS3 SCIENCE - PHYSICS ©2003, STEVE PARKER

3. 1 1 KS3 SCIENCE - PHYSICS KS3 SCIENCE - PHYSICS Waves

4. WAVE PROPERTIES 2 2

5. 3 3 A wave is a repeating, continuous movement A wave is a repeating, continuous movement

6. WAVE PROPERTIES 4 4 A wave carries energy but without any transfer of matter A wave carries energy but without any transfer of matter

7. WAVE PROPERTIES 5 5 The “Wavelength” is the distance taken to travel a complete wave The “Wavelength” is the distance taken to travel a complete wave

8. WAVE PROPERTIES 6 6 The “Amplitude” is the distance from the middle to the peak or trough The “Amplitude” is the distance from the middle to the peak or trough

9. WAVE PROPERTIES 7 7 The “Frequency” is the number of completed waves that pass a certain point each second - the “Period” is the time for a complete wave to pass The “Frequency” is the number of completed waves that pass a certain point each second - the “Period” is the time for a complete wave to pass

10. WAVE PROPERTIES 8 8 Most waves are “Transverse”, e.g. waves on water, or light - vibrations are at right-angles to the direction of travel as in this diagram Most waves are “Transverse”, e.g. waves on water, or light - vibrations are at right-angles to the direction of travel as in this diagram VIBRATIONVIBRATIONTRAVELTRAVEL

11. WAVE PROPERTIES 9 9 Some waves are “Longitudinal”, e.g. sound and shock waves - vibrations are along the direction of travel Some waves are “Longitudinal”, e.g. sound and shock waves - vibrations are along the direction of travel VIBRATIONVIBRATIONTRAVELTRAVEL

12. WAVE PROPERTIES 10 WAVELENGTH COMPRESSION RAREFACTION

13. ELECTROMAGNETIC WAVES 11

14. ELECTROMAGNETIC WAVES 12 Radio Waves Radio Waves Micro Waves Micro Waves Infra Red Infra Red Ultra Violet Ultra Violet X- Rays X- Rays Gamma Rays Gamma Rays Visible Light Visible Light Electromagnetic waves are waves that carry electrical and magnetic energy, and there is a whole spectrum Electromagnetic waves are waves that carry electrical and magnetic energy, and there is a whole spectrum

15. ELECTROMAGNETIC WAVES 13 Electromagnetic waves are waves that carry electrical and magnetic energy, and there is a whole spectrum Electromagnetic waves are waves that carry electrical and magnetic energy, and there is a whole spectrum Radio Waves Radio Waves Micro Waves Micro Waves Infra Red Infra Red Ultra Violet Ultra Violet X- Rays X- Rays Gamma Rays Gamma Rays Visible Light Visible Light LONGER WAVELENGTHS LONGER WAVELENGTHS SHORTER WAVELENGTHS SHORTER WAVELENGTHS

16. PRACTICAL USES 14

17. 15 PRACTICAL USES Infrared waves are used in remote controls and also for night vision Infrared waves are used in remote controls and also for night vision

18. 16 PRACTICAL USES Microwaves are used for cooking and for mobile telephones Microwaves are used for cooking and for mobile telephones

19. 17 PRACTICAL USES Radio waves are used for communication and entertainment Radio waves are used for communication and entertainment

20. 18 PRACTICAL USES Ultra violet waves, X-Rays and Gamma Rays can all cause types of cancer Ultra violet waves, X-Rays and Gamma Rays can all cause types of cancer

21. 19 PRACTICAL USES However, in small doses, X-Rays are useful for checking broken bones and Gamma Rays can be used to treat some cancers However, in small doses, X-Rays are useful for checking broken bones and Gamma Rays can be used to treat some cancers