1. Chapter 11 Section 1

2. What’s a wave? Wave: Repeating disturbance that transfers energy Wave travels only as long as it has energy Waves travel through medium or without medium Mechanical waves need a medium Vacuum waves do not need a medium Two main kinds of wave: Transverse wave (shear): Can travel through medium but does not need to Longitudinal wave (compressional): Must travel through medium

3. What causes waves? Waves are the result of some vibration Wave on a String 2.00 PhET Wave on a String - Interference, Harmonic Motion, Frequency, Amplitude PhET Wave on a String - Interference, Harmonic Motion, Frequency, Amplitude

4. Transverse Waves Also called shear waves Movement is perpendicular to direction of wave Example: light

5. Longitudinal Wave Movement is parallel to direction of wave Example: sound Movement is a series of compressions and rarefactions and requires medium Compression: particles come together Rarefaction: particles move apart

6. Which kind is it? Test yourself: Which kind of wave? Yes, it’s longitudinal!

7. Which kind is it? Which kind of wave? Yes, it’s transverse!

8. Other Media! Water waves: Formed by wind blowing over surface of water Wave is combination of transverse and longitudinal Overall motion is circular

9. Other Media! Seismic waves: – Waves moving through Earth materials due to earthquake – Longitudinal waves move through solids and fluids and are called P waves – Transverse waves move through solids and are called S – Surface waves move along surface, called Rayleigh and Love waves Similar to water waves

10. Seismic Waves