1. Do now! Can you stick the sheet in?

2. Topic 3 Waves

3. This lesson What is a wave? Longitudinal and transverse waves Amplitude, wavelength, frequency and period of a wave The relationship between frequency and period The wave equation

4. What is a wave? YouTube - Water bubble in Space (zero gravity)

5. Waves Waves can transfer energy and information without a net motion of the medium through which they travel. They involve vibrations (oscillations) of some sort.

6. Waves Waves can transfer energy and information without a net motion of the medium through which they travel. They involve vibrations (oscillations) of some sort. Can you do something very boring and traditional……… Can you copy this please?

7. Rays Rays highlight the direction of energy transfer.

8. Transverse waves The oscillations are perpendicular to the direction of energy transfer. Direction of energy transfer oscillation

9. Transverse waves peak trough

10. Transverse waves Water ripples Light On a rope/slinky Earthquake

11. Longitudinal waves The oscillations are parallel to the direction of energy transfer. Direction of energy transfer oscillation

12. Longitudianl waves compression rarefraction

13. Longitudinal waves Sound Slinky Earthquake

14. Wave measurements

15. Amplitude - A The maximum displacement from the mean position. amplitude

16. Period - T The time taken (in seconds) for one complete oscillation. It is also the time taken for a complete wave to pass a given point. One complete wave

17. Frequency - f The number of oscillations in one second. Measured in Hertz. 50 Hz = 50 vibrations/waves/oscillations in one second.

18. Period and frequency Period and frequency are reciprocals of each other f = 1/TT = 1/f

19. Wavelength - λ The length of one complete wave. wavelength

20. Wave speed - v The speed at which the wave fronts pass a stationary observer. 330 m.s -1

21. The Wave Equation The time taken for one complete oscillation is the period T. In this time, the wave will have moved one wavelength λ. The speed of the wave therefore is distance/time v = λ/T = fλ v λ f x

22. The Wave Equation The time taken for one complete oscillation is the period T. In this time, the wave will have moved one wavelength λ. The speed of the wave therefore is distance/time v = fλ v λ f x Can you copy this part please?

23. 1)A water wave has a frequency of 2Hz and a wavelength of 0.3m. How fast is it moving? 2)A water wave travels through a pond with a speed of 1m/s and a frequency of 5Hz. What is the wavelength of the waves? 3)The speed of sound is 330m/s (in air). When Dave hears this sound his ear vibrates 660 times a second. What was the wavelength of the sound? 4)Purple light has a wavelength of around 6x10 -7 m and a frequency of 5x10 14 Hz. What is the speed of purple light? Some example wave equation questions 0.2m 0.5m 0.6m/s 3x10 8 m/s

24. Let’s try some questions! Page 125 (all the questions) and page 136 questions 1 and 4.