Reading Assignment [ R-3 ]

Read Chapter 3 of the textbook.

Upload a Word (.doc or .docx) or PDF file to Canvas with answers to the following questions. Put a blank line between each answer in order to make it easier to read. Use your own words. After the definition each term, create an example of using the word in a sentence. Example:

Vocabulary

1. medium
2. impulse
3. longitudinal
4. air column
5. compression
6. rarefaction
7. wavelength
8. wave front
9. Doppler Effect
10. reflection
11. diffraction
12. interference
13. beats
14. sound intensity

In addition to defining the above vocabulary, answer the following questions in your own words.

1. If you were standing on the surface moon and your rocket ship blew up 100 meters away, would you be able to hear it? Why (not)?
2. How many compressions are showing in Fig. 10d?
3. How many rarefactions are showing in Fig. 10a?
4. Why is the speed of sound higher when the air is warmer?
5. What will the speed of pressure waves in air be at 10° centigrade: (a) in meters per second; and (b) in feet per second? Hints: Speed in air ≅ 331.4 meters/sec + (0.6 meters/sec x Temperature in Celsius). One meter ≅ 3.3 feet. Check your work.
6. Someone claps their hands in front of a wall 200 meters away. How many seconds later will they hear the echo, if the temperature is 20° Celsius.
7. Why do you think the pitch is higher when someone talks after sucking in helium?
8. Why does the sound of a car horn sound different to a person standing on the side of the road compared to the driver of the car?
9. Why is reflection of pressure waves more common than refraction?
10. When a pressure waves approaches you from the right side of your head and then bend around your head to reach your left ear, is that reflection, refraction, or diffraction?
11. Why is it that the points along the dotted line labelled "c" in Fig. 19a cause constructive interference?
12. Why is it that the points along the dotted line labelled "d" in Fig. 19a cause destructive interference?
13. What is the beat frequency if two strings are plucked, one playing at 440 Hz, and the other at 442 Hz?
14. How do the sound intensities compare between a pressure wave passing by a listener 3 meters away, with the intensity as it continues on and passes another listener 9 meters away? (Hint: Intensity ∝ 1 / Distance²)