1. General, Organic, and Biological ChemistryCopyright © 2010 Pearson Education, Inc. Grades close this Friday. Please complete all make-up work by then. 1

2. General, Organic, and Biological ChemistryCopyright © 2010 Pearson Education, Inc. Homework Assignment: Vocabulary 2

3. General, Organic, and Biological ChemistryCopyright © 2010 Pearson Education, Inc. When a tree falls in the forest, and there is no one to hear it, does it make a sound? 3

4. General, Organic, and Biological ChemistryCopyright © 2010 Pearson Education, Inc. What is the last sense to go, when you are dying? 4

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

6. General, Organic, and Biological ChemistryCopyright © 2010 Pearson Education, Inc. Where does sound come from? 1) All sounds are produced by the vibrations (moving back and forth) of objects 2)Examples: guitar string, vocal chords, drum 3) The original vibration sets something larger in motion (guitar, chest/throat) 6

7. General, Organic, and Biological ChemistryCopyright © 2010 Pearson Education, Inc. This sets air in motion…which result in compressions and rarefactions  Compression: compressed air from a pulse  Rarefaction: the empty space (low pressure) area behind the compression 7

8. General, Organic, and Biological ChemistryCopyright © 2010 Pearson Education, Inc. This results in a longitudinal wave…sound travels in a longitudal wave 8

9. General, Organic, and Biological ChemistryCopyright © 2010 Pearson Education, Inc. Longitudinal wave Definition: A wave in which the vibration is in the same direction as the wave is traveling 9