1. Waves!!

2. What are waves?? WAVES are regular or rhythmic disturbances that carry energy through matter or space. Remember, a wave is really just an energy carrier! A wave will travel only as long as it has ENERGY to transfer.

3. What are waves? Waves transfer energy WITHOUT transporting matter from place to place. Anything that moves up and down or back and forth in a rhythmic way is VIBRATING All waves are produced by something that VIBRATES.

4. Two Types 1. Mechanical Waves- waves that can travel only through matter. Travel slowly! Examples: water, sound 2. Electromagnetic Waves- waves that do not require matter to carry energy. Travel at the speed of light! Examples: TV, radio, microwave, X-ray (look at chart)

5. Electromagnetic Spectrum

7. Two Types 1. Mechanical Waves It does matter if the molecules are in a SOLID, LIQUID, or GAS, as long as something is there for the wave to travel through. 2. Electromagnetic Waves They can travel through a VACUUM. The biggest VACUUM is space.

8. Two Types 1. Mechanical Waves MECHANICAL WAVES travel the fastest through SOLIDS and slowest through GASES. 2. Electromagnetic Waves Importance to universe???

9. Importance to Universe

10. MEDIUM is the material in which the wave travels through.

12. Wave Shape 1. TRANSVERSE WAVES - matter moves back and forth at right angles to the direction the wave travels. In other words, they repeat, bump after bump, kind of like a chain of mountains.

13. Wave Shape

14. A. CREST are high points on the wave. B. TROUGH are low points on the wave. C. All ELECTROMAGNETIC WAVES are transverse waves.

15. Wave Shape 2. COMPRESSIONAL WAVES - matter in the medium moves forward and backward in the direction the wave travels. –a. COMPRESSION is when the particles are squeezed together. –b. RAREFACTIONS are where the particles are spaced far apart. –c. SOUND waves are compressional waves.

16. Wave Shape

17. Page 3 Answers 1. EM, transverse 2. Mechanical, compressional 3. Mechanical, compressional 4. All of them 5. Transverse 6. compressional 7. EM 8. Rarefaction 9. Transverse 10. Crest 11. Trough 12. Transverse 13. Any EM wave! 14. compression

18. Wave Properties 1. AMPLITUDE is the measure of the ENERGY a wave carries or transfers. **The greater the AMPLITUDE, the more energy the wave transfers. - AMPLITUDE of a transverse wave is half the distance between a crest and a trough. –In a compressional wave, the tighter the medium is pushed together at a compression, the larger the AMPLITUDE.

19. Wave Properties 2. WAVELENGTH is the distance between a point on one wave, and the identical point on the next wave. For example, from crest to crest or trough to trough. - In transverse wave, from crest to crest or trough to trough. –In a compressional wave, from one COMPRESSION to the next or from one RAREFACTION to the next.

20. Wave Properties 3. FREQUENCY of a wave is the number of waves that pass a given point in one second. It is measured in waves per second or Hertz (Hz).

21. Wave Properties 4. PERIOD - the amount of time it takes one wavelength to pass a point –measured in seconds –formula: 1/frequency

22. Put It All Together!! **** As FREQUENCY of a wave increases, the PERIOD decreases. ****As frequency INCREASES, wavelength DECREASES. IMPORTANT!!

23. Determining Wave Speed Formula: v = f. λ – Velocity/speed = Frequency Wavelength – m/sec = Hz m/cm

24. Determining Wave Speed 1. What is the speed of a sound wave that has a wavelength of 2m and a frequency of 170.5Hz?

25. Determining Wave Speed 2. The speed of a wave on a rope is 50cm/sec and its wavelength is 10cm. What is the frequency?

26. Determining Wave Speed 3. The speed of an oncoming ocean wave is 6cm/sec. The length between two successive wave crests is 3m. What is the wave’s frequency?

27. Pg. 6 Answers 1. Crest, trough 2. More 3. Crest to crest 4. Second, frequency 5. Lower, higher 6. Amplitude 7. Amplitude 8. wavelength 9. Wavelength 10. 2m 11. 1m