SPH 3U Review of Sound

SPH 3U Review of Sound

1.  A pendulum swings back and forth 20 times in 15 s. Calculate its period and its frequency.

2.  A swimmer notices that 30 waves strike a breakwater (wall) in 1.00 min. What is the period of the waves in seconds?

3.  Determine the period of each of the following.

a)  The pulse from a human heartbeat that is heard 24 times in 15 s.

b)  A tuning fork that vibrates 2048 times in 8.0 s.

4.  Calculate the frequency of each of the following periods.

a)  5.0 s c) 2.5 x 10-2 s

b)  0.80 s d) 0.40 min

5.  Calculate the period of each of the following frequencies.

a)  10 Hz c) 500 kHz

b)  0.25 Hz d) 3.5 Hz

6.  The horizontal distance between the end points in the swing of a pendulum is 8.0 cm. What is the amplitude?

7.  The tine (prong) of a tuning fork, when struck, has an amplitude of 0.13 cm. If the frequency of the fork is 200 Hz, what total distance will the tine travel in 1.00 min?

8.  A cross section of a wave is shown at right. Name the parts of the wave indicated by the letters on the diagram.

9.  If the crest of a wave takes 2.0 s to travel to the position of another crest 30 cm away,

a)  what is the speed of the wave?

b)  what is the frequency of the wave?

c)  what is the frequency of the source?

10.  Bats emit ultrasonic sound to help them locate obstacles. The sound waves have a frequency of 5.5 x 104 Hz. If they travel at 350 m/s, what is their wavelength?

11.  What are the wavelengths in air of the lowest and the highest audible frequencies of human hearing if the speed of sound is 342 m/s? What are frequencies above human range called?

12.  Explain the difference between refraction and diffraction using diagrams and an example.

13.  Standing waves are produced in a string by 2 waves traveling in opposite directions at 6.0 m/s. The distance between the 2nd node and the 6th node is 80 cm. Determine the wavelength and the frequency of the original waves.

14.  5.0 Hz waves move along a rope with a wavelength of 40 cm. What is their speed?

15.  Standing waves are produced in a string by sources at each end with a frequency of 10.0 Hz. The distance between the third and the sixth node is 54 cm.

a)  What is the wavelength of the interfering waves? b) What is their speed?

16.  A wave can reflect off two types of surfaces: “hard” and “free”. What is the difference in reflection of incoming waves on these two types? Use a diagram to explain.

17.  The distance between successive crests in a series of water waves is 5.0 m, and the crests travel 8.6 m in 5.0 s. Calculate the frequency of a block of wood bobbing up and down in the water.

18.  Draw a longitudinal wave and label it.

19.  Two pulses of equal amplitude approach each other from opposite directions. When they meet, what type of interference will result? What is the name of that result?

20.  Describe the two types of interference of waves. Explain how this phenomenon is heard when you walk in front of two speakers producing the same sound signal (ie. equal frequencies).

21.  How does a speaker project sound? How does the ear hear that sound?

22.  A high-pitched sound increases in volume. What characteristic of the sound wave has changed? What affects the pitch of a sound?

23.  How can resonance cause a wine glass to at first sing, and then possibly shatter?

24.  Two vibrating tuning forks are brought close together and 18 beats are heard every 3.0 s. What could the frequencies of the second fork be if the first has a frequency of 256 Hz?

25.  The 1st resonant length of a closed air column is 12 cm. What is the 2nd resonant length? 3rd?

26.  A 1.2 m open-air column sings when a 256 Hz tuning fork is placed beside it. If the column is stretched to 1.8 m, it also sings. What is the speed of sound in the air column?

27.  A tuning fork vibrating at 256 Hz is brought beside a resonating box and then removed. Why can you hear a sound coming from the box? What is the frequency of that sound? If the box is the first resonant length and measures 33.5 cm in length, what is the temperature of the air?

28.  How can a singer use her voice to smash a wine glass?

29.  Near the track watching a Formula-1 car race, you hear the 1st place car whiz by, emitting a high-pitched whine. As it goes down the track, the whine fades to a buzzing sound. Explain why.

30.  Describe how a sonic boom is formed and heard by an observer. Describe the relationship of a sonic boom to the Doppler effect.

Textbook: p. 264 #1, 2, 3, 4, 5, 19

p. 288 #1, 2, 3, 5, 6, 7, 10, 13, 17, 24, 39

p. 318 #1, 2, 3, 5, 9, 32

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