What are waves?

1. MT 6 LT 1 Mechanical Waves What are waves?

2. Background Knowledge: Waves • What are some examples of waves? • Why are waves important?

3. What causes waves? • Waves are created when a source of Energycauses a medium to vibrate. • WAVES NEED ENERGY TO MOVE • A vibration is a repeated back and forth or up and down motion.

4. What are the different types of Wave? • Mechanical Waves • Sound Waves • Electromagnetic Waves

5. This LT will focus on Mechanical Waves

6. What are mechanical waves? • Definition: A disturbance that transfers energy from place to place. • They need a source of energy to produce it

7. How are waves & energy related? • A wave transports energy along a Mediumwithout transporting matter.

8. Mediums & Waves • What do mechanical waves move through? • A medium • Mechanical waves require a medium in order to travel from one place to another • Can be gas, liquid, or solid. • Waves in different mediums travel at different speeds.

9. Mediums & Waves • What do mechanical waves move through? • Mechanical Waves do NOT move the medium from one place to another • Note that Not all waves require a medium to travel. • Example: Light from the sun travels through empty space.

10. What determines the speed of a Mechanical Wave? • The speed of a wave is determined by its: • Wavelength x Frequency

11. What are the different types of Mechanical Waves?

12. What are the different types of Mechanical Waves? • Waves are classified according to how they move. • 3 types of Waves: • Transverse Wave • Longitudinal Wave • Surface Wave

13. What is a Transverse Wave? • A wave that travels in the opposite direction (perpendicular) to the medium in which it is traveling through • Transverse means across.

14. Basic Properties of Transverse Waves (What are the parts of a Transverse Wave?) • Crest • Trough • Amplitude • Energy • Wavelength

15. Basic Properties of Transverse Waves (What are the parts of a Transverse Wave?) • Crest • The highest point of the wave above the rest position • Trough • The lowest point below the rest position

16. Transverse Wave: Amplitude • Amplitude is the distance from the rest to crest or rest to trough. • The farther a medium moves as it vibrates, the larger the amplitude. Rest

17. Transverse Wave: Amplitude • The Amplitude tells us the amount of energy being transported. • High Energy = High Amplitude • Low Energy = Low Amplitude.

18. Transverse: Wavelength • A wave travels a certain distance before it repeats. • When it repeats, it is knows as the Wavelength • The wavelength is the distance between 2 corresponding (same/related) parts of a wave . • Measured from crest to crest or trough to trough.

19. Wave Height • The distance from one crest to one trough (trough to crest too)

20. Draw a Transverse Wave and label: crest & trough

21. Properties of Longitudinal/Compressional Waves

22. Longitudinal Wave • The vibration of the medium is the same direction (parallel) to the direction in which the wave travels. • Example: Slinky

23. Longitudinal Wave • Compressions: • The parts where the coils are close together • Rarefactions • the parts where the coils are spread out

24. What is a Surface Wave?

25. Surface Waves • A wave that travels along a surface separating two media