UNIVERSITY OF TORONTO Faculty of Arts and Science MOCK EXAMINATION PHY207H1S. Duration 3 hours NO AIDS ALLOWED

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1 UNIVERSITY OF TORONTO Faculty of Arts and Science MOCK EXAMINATION PHY207H1S Duration 3 hours NO AIDS ALLOWED Instructions: Please answer all questions in the examination booklet(s) provided. Completely fill out your identifying information on each booklet you use, and number your booklets. On each page clearly indicate at the top which question you are answering or continuing. The examination has 6 pages, including this cover page, and page 2 which is Possibly Helpful Information. There are 12 questions, but they are not all weighted equally. Here is the mark breakdown: 1. 2 points 2. 2 points points points 5. 2 points 6. 2 points points points 9. 2 points points points points Total: 102 points

2 PHY207H1S Physics of Music Mock Exam - Page 2 of 6 Possibly helpful information: Piano Key Number Note name Freq. [Hertz] Piano Key Number Note name Frequency [Hertz] 1 A F A# F# B G C G# C# A D A# D# B E C F C# F# D G D# G# E A F A# F# B G C G# C# A D A# D# B E C F C# F# D G D# G# E A F A# F# B G C G# C# A D A# D# B E C F C# F# D G D# G# E A F A# F# B G C G# C# A D A# D# B E C Speed of sound in air: 343 m/s

3 PHY207H1S Physics of Music Mock Exam - Page 3 of 6 Question 1 [2 points for letter of best answer no reasoning required for full marks] Above are plots of y (vertical axis) versus x (horizontal axis) for three different waves. Which of the functions shown in the graphs could most easily be made up as a sum of sinusoidal waves? A. A B. B C. C D. None of these functions could be made up as a sum of sinusoidal waves. Question 2 [2 points for letter of best answer no reasoning required for full marks] A mass hangs on a spring but isn t moving. You pull it down 2 cm, and release it, and it starts oscillating up and down with some amplitude and frequency. You then repeat the experiment with the same mass and the same spring, but this time you pull it down 4 cm and release it. How does the new amplitude and frequency compare to the old? A. Both the amplitude and frequency are the same as before. B. The frequency is higher than before, but the amplitude is the same. C. The amplitude is higher than before, but the frequency is the same. D. The amplitude is higher than before, but the frequency is lower than before. E. The frequency and amplitude are both higher than before. Question 3 a. [5 points] When you turn up the headphones volume on your iphone, the sound originally entering your ears at 50 decibels is boosted to 80 decibels. By what factor is the intensity of the sound has increased? b. [5 points] A speaker is in a large, open space, and your ear is 1 m away from it. You hear a sound intensity level of 80 decibels at that distance. To what distance away from the speaker should you move your ear so that you hear a sound intensity level of 60 decibels? Question 4 [20 points] What is damped harmonic motion, and what role does it play in music? As part of your description, be sure to explain what the envelope is, and describe the role of energy in damped harmonic motion. Also mention the attack-decay-sustain-release envelope model, and how this relates to damped harmonic motion.

4 PHY207H1S Physics of Music Mock Exam - Page 4 of 6 Question 5 [2 points for letter of best answer no reasoning required for full marks] Suppose you shake the end of a stretched string to produce a wave. Which of the following actions would increase the speed of the wave down the string? A. Move your hand up and down more quickly as you generate the wave B. Move your hand up and down a greater distance as you generate the wave C. Stretch the string tighter to increase the tension D. Loosen the string to decrease the tension E. None of these changes would increase the speed of the wave Question 6 [2 points for letter of best answer no reasoning required for full marks] Above are plots of y (vertical axis) versus x (horizontal axis) for three different waves. All three waves travel to the right with the same speed. Which wave has the highest frequency? A. Wave A B. Wave B C. Wave C D. All waves have the same frequency E. Impossible to determine from the information given

5 PHY207H1S Physics of Music Mock Exam - Page 5 of 6 Question 7 a. [6 points] When you plot a waveform of a sound, what is plotted on the horizontal and vertical axes? When you plot a Fourier spectrum of a sound, what is plotted on the horizontal and vertical axes? b. [2 points] Draw a sketch of a waveform and Fourier Spectrum for a pure tone. You do not need to label your axes. c. [2 points] Draw a sketch of a waveform and Fourier Spectrum for white noise. You do not need to label your axes. Question 8 a. [6 points] Describe an advantage and a disadvantage of the Diatonic Scale. b. [2 points] What is the ratio of frequencies of a perfect fourth and a perfect fifth on the diatonic scale? c. [6 points] Describe an advantage and a disadvantage of the Equal Tempered Scale. d. [2 points] Using an Equal Tempered Scale, if the lower note is a C#, what would be the upper note of a perfect fourth and a perfect fifth? e. [4 points] Which scale, Diatonic or Equal Tempered, is used most often in modern Western music, and why? Question 9 [2 points for letter of best answer no reasoning required for full marks.] A sound wave with an intensity of 50 mw/m 2 hits wall in a recording studio. The reflected wave has an intensity of 20 mw/m 2. What is the intensity of the sound wave transmitted into the wall? A. zero B. 10 mw/m 2 C. 20 mw/m 2 D. 30 mw/m 2 E. 50 mw/m 2 Question 10 [2 points for letter of best answer no reasoning required for full marks] For a string instrument like a violin, the primary oscillations are resonant oscillator makes use of standing waves. A. Longitudinal, transverse B. Longitudinal, Longitudinal C. Transverse, Longitudinal D. Transverse, Transverse standing waves and the

6 PHY207H1S Physics of Music Mock Exam - Page 6 of 6 Question 11 [10 points] Consider a trumpet, as shown in the diagram below, with some labeled parts. Identify the five parts of the Five Part Model for the trumpet. (Note that not all parts may be included in this diagram, and also the diagram includes labeled parts which are not part of the five part model.) Question 12 a. [10 points] Describe how a dynamic microphone works. Be sure to mention the most important parts of the microphone, and how electromagnetic induction plays a part. b. [10 points] Describe how a speaker works. How is the functioning of a speaker similar to a microphone, and what are the differences?