1. Lesson 1

2. Watch the Slinky… Slinky videos http://www.youtube.com/watch?v=VnfiZfyQ2yw http://www.youtube.com/watch?v=upcTmdqrEeo

3. What is a Wave? Transfer of energy In the form of disturbance through some medium* Without translocation of the medium * Not all waves require a medium

4. Transverse Waves http://www.surendranath.org/Applets/Waves/Twave01 /Twave01Applet.html http://www.surendranath.org/Applets/Waves/Twave01 /Twave01Applet.html

5. Longitudinal Waves http://www.surendranath.org/Applets/Waves/Lwave01 /Lwave01Applet.html http://www.surendranath.org/Applets/Waves/Lwave01 /Lwave01Applet.html

6. Descriptions

7. Wave Terminology Crest/Peak – high point of a transverse wave Trough – low point of a transverse wave crest trough

8. Wave Terminology (In a longitudinal wave) Compression – region of high pressure Rarefaction – region of low pressure

9. Wave Terminology Phase – two points are said to be in phase if they are moving in the same direction and speed, with the same displacement from the rest position p q p” q” p’ q’

10. Wave Terminology Wavefront – Imaginary line joining all points in the same phase of vibration (e.g. all the crests)

11. Quantities

12. Wave Terminology Amplitude – maximum displacement of a particle from its mean position (on either side) SI Unit: m A A AA A A

13. Wave Terminology Wavelength – distance between two successive particles which are oscillating in phase SI Unit: m

14. Wave Terminology Frequency (f): number of vibrations/oscillations/cycles in 1 second. SI Unit: s -1 or Hz Period (T): time taken for one complete vibration/oscillation/cycle. SI Unit: s T = 1/f

15. Calculating wave speed

16. Wave Equation Wave speed/velocity (v): distance moved by the wave in one second SI Unit: ms -1 (Discuss) How to calculate v using the wave quantities covered earlier?

17. Wave Equation With the wavelength and frequency of a wave, we know how many waves and how far the series of waves will cover per unit time. This is known as wave speed – distance traveled by a wave per unit time. Recall speed = So for waves, speedv =distance covered in 1 cycle time taken to cover 1 cycle Recall f so speed of waves v = Speed equation for waves v = (Unit : ms -1 ) Speed equation for waves v = f (Unit : ms -1 )

18. Test yourself… A fisherman notices that wave crests pass the bow of his anchored boat every 3.0s. He measures the distance between two successive crests to be 6.5m. How fast are the waves travelling?

19. Complete pages 1, 3, 7 of the Class Worksheet (Notes).