Reading Assignment [ R-4 ]

Read Chapter 4 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.

Vocabulary

1. standing wave
2. node
3. antinode
4. fundamental mode
5. octave
6. closed tube
7. membrane
8. soundboard
9. resonance
10. resonance frequency
11. Helmholtz resonator

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

1. In how many ways (modes) do most things vibrate? Do they vibrate with just one frequency at a time?
2. Why can't you see the many vibrations happening in a plucked string when you look at it?
3. When the two waves in Fig. 1(a) on p. 57 pass through a string do they interfered constructively or destructively?
4. When the two waves in Fig. 1(c) pass through a string do they interfered constructively or destructively?
5. When the two waves in Fig. 1(e) pass through a string do they interfered constructively or destructively?
6. Which of the four vibration modes of a string shown in Fig. 3 on p. 59 is the fundamental mode?
7. If the frequency of the fundamental mode for a plucked string shown in Fig. 3(a) is 50 Hz, what would the frequencies of the modes in Fig. 3(b), 3(c), and 3(d) be?
8. What happens to the shape of an impulse reaches a fixed end? Is it reflected back with the same shape, or is it inverted (i.e. upside down)?
9. If a note has a pitch of 100 Hz, what will the pitch be if it is raised an octave?
10. What is the vibration pattern of a plucked string a mixture of?
11. Is the wave traveling down a string transverse or longitudinal?
12. Is the wave traveling down an air column transverse of longitudinal?
13. The lowest mode frequencies F₁, F₂, F₃, and F₄ for a closed tude are the odd integer multiples 1xF₁, 2xF₁, 3xF₁, and 4xF₁. If the fundamental mode frequency F₁ if 100 Hz, what would the frequencies be for F₂, F₃, and F₄?
14. What causes the "clang" when a tuning fork (or piano string) is hit with a hammer?
15. Can you see any effect of resonance on a child on a swing? How are they able to gradually increase the magnitude of the swing, and then maintain it?
16. Helmholtz resonators were used to investigate the different frequencies that are part of a complex vibration. Why did they come in different sizes?