1. General, Organic, and Biological ChemistryCopyright © 2010 Pearson Education, Inc. Review 1)What is the unit for speed (velocity)? 2)What is the unit for frequency? 3)What is the unit for wavelength? 4)What are the symbols for velocity, frequency, wavelength? m/s vib/s or Hertz m v, f, λ 1

2. General, Organic, and Biological ChemistryCopyright © 2010 Pearson Education, Inc. Review 4)How do bees buzz? 5)Which has a higher sound,a bee or a mosquito? 6)Why? Wings vibrating Mosquito Mosquito’s wings vibrate faster… Bees (200 vib/s) Mosquito (300-600 vib/s) 2

3. General, Organic, and Biological ChemistryCopyright © 2010 Pearson Education, Inc. Review  What is a wavelength?  What is a frequency?  What is a velocity? The distance between 2 identical parts of a wave How fast something vibrates The speed of an object 3

4. General, Organic, and Biological ChemistryCopyright © 2010 Pearson Education, Inc. What is the name of this type of wave? Longitudinal Is it a sound or light wave? Sound 4

5. General, Organic, and Biological ChemistryCopyright © 2010 Pearson Education, Inc. Pitch 5

6. General, Organic, and Biological ChemistryCopyright © 2010 Pearson Education, Inc. Pitch- how high or low the frequency of sound is  http://www.sanpedro.com/spcom/foghorn.htm http://www.sanpedro.com/spcom/foghorn.htm  http://www.youtube. com/watch?v=O4qo JZjRG9A http://www.youtube. com/watch?v=O4qo JZjRG9A Humans can hear frequencies in the range of 20 – 20 000 Hz (normal) 6

7. General, Organic, and Biological ChemistryCopyright © 2010 Pearson Education, Inc. Infrasonic  Infrasound is low frequency sound, inaudible to human, although we may feel the very slow vibrations. 7

8. General, Organic, and Biological ChemistryCopyright © 2010 Pearson Education, Inc. Animals and Infrasonic Earthquake waves and finding oil are infrasound. Elephants ( 6 miles), whales (hundreds of miles) and some other large animals can hear/produce infrasound  http://en.wikipedia.org/wiki/W hale_song#Song_of_the_Hu mpback_Whale http://en.wikipedia.org/wiki/W hale_song#Song_of_the_Hu mpback_Whale 8

9. General, Organic, and Biological ChemistryCopyright © 2010 Pearson Education, Inc. Ultrasound Ultrasound is high frequency sound, above 20 000 Hz, too high to be heard by humans. Ultrasound echoes can be used to measure distance (SONAR) and to see inside objects (scans). 9

10. General, Organic, and Biological ChemistryCopyright © 2010 Pearson Education, Inc. Animals and Ultrasonic bats and dolphins- can hear frequencies up to 100 000 Hz dogs – 40 000 to 60 000 Hz http://www.youtube.com/wat ch?v=M_MAGGIOx-A 10

11. General, Organic, and Biological ChemistryCopyright © 2010 Pearson Education, Inc. Remember…we can’t hear “infra” (below) or “ultra” (above) sonic 11