Sound 179 



12. Why will "an ear to the ground" bring us many sounds before we 

 can hear them by standing erect? 



13. What is meant by the reflection of sound? 



14. Is the distance sound "carries" affected by the wind? Why? 



15. Does the direction from which sound comes to us affect our hearing 

 of it? 



16. Is it true or false that sound travels faster than light? Give one 

 reason for your answer. 



PROJECTS 



1. Demonstrate the transmission of sound through liquids. 



2. Demonstrate the structure and function of the ear by the use of a 

 model. 



OUTDOOR OBSERVATION 



Observe how familiar outdoor sounds in your general neighborhood 

 are affected in intensity and clearness by wind, fog, and other weather 

 conditions. Observe if they are different by day than by night. Record 

 your observations. 



REFERENCES 



Introductory Physics, Ch. VIII Higgins 



The World of Sound Bragg 



