Chapter 11 Waves Exam Prep

Physics, 9e (Giambattista)

Chapter 11 Waves

1) The intensity of the sound wave from an airplane is 1.0 × 102 W/m2 at 5.0 m. What is the intensity at 100 m?

A) 0.25 W/m2

B) 0.53 W/m2

C) 5.0 W/m2

D) 0.25 mW/m2

2) A sound source of power 100 watts radiates sound uniformly in all directions. The intensity of the sound at a distance of 4.00 m is

A) 0.301 W/m2.

B) 0.353 W/m2.

C) 0.497 W/m2.

D) 0.535 W/m2.

E) 0.621 W/m2.

3) A sound source of power 150 watts radiates sound uniformly in all directions. The intensity of the sound at a distance of 4.00 m is

A) 0.389 W/m2.

B) 0.403 W/m2.

C) 0.582 W/m2.

D) 0.746 W/m2.

E) 0.927 W/m2.

4) A sound source radiates sound uniformly in all directions. The intensity of the sound at a distance of 100 m is 1.00 × 10−4 W/m2. The power output of the sound source is

A) 12.6 W.

B) 16.2 W.

C) 20.4 W.

D) 24.5 W.

E) 30.6 W.

5) What is the distance between adjacent nodes in a standing wave?

A) wavelength/4

B) wavelength/3

C) wavelength/2

D) wavelength/1

6) What is the distance between a node and an adjacent antinode in a standing wave?

A) wavelength/1

B) wavelength/2

C) wavelength/3

D) wavelength/4

7) Standing waves are produced by the superposition of two waves with

A) the same amplitude, frequency, and direction of propagation.

B) the same amplitude, frequency, and opposite direction of propagation.

C) the same amplitude, different frequencies, and opposite direction of propagation.

D) the same amplitude, different frequencies, and same direction of propagation.

8) A string is stretched with a tension of 120 N. The string has a mass of 10.0 grams and has a length of 2.50 meters. The velocity of wave propagation along the string is

A) 125 m/s.

B) 142 m/s.

C) 173 m/s.

D) 185 m/s.

E) 217 m/s.

9) A string is stretched with a tension of 120 N. The string has a length of 2.5 meters. The velocity of wave propagation along the string is 220 m/s. The mass per unit length of the string is

A) 5.8 × 10−3 kg/m.

B) 5.0 × 10−3 kg/m.

C) 4.2 × 10−3 kg/m.

D) 3.7 × 10−3 kg/m.

E) 2.5 × 10−3 kg/m.

10) A string is stretched with a tension of 100 N. The string has a length of 2.00 meters. The velocity of wave propagation along the string is 220 m/s. The mass of the string is

A) 3.75 g.

B) 4.13 g.

C) 4.66 g.

D) 5.21 g.

E) 5.74 g.

11) A string with a length of 1.20 m has a mass of 4.00 g. The velocity of wave propagation along the string is 185 m/s. The tension of the stretched string is

A) 162 N.

B) 145 N.

C) 130 N.

D) 114 N.

E) 102 N.

12) A string with a length of 2.50 m has a mass of 5.00 g. The velocity of wave propagation along the string is 210 m/s. The tension of the stretched string is

A) 88.2 N.

B) 75.0 N.

C) 70.2 N.

D) 66.7 N.

E) 60.2 N.

13) A string on a guitar is stretched between two points 35.0 cm apart with a tension of 65.0 N. The mass/length of the string is 0.00400 kg/m. The velocity of wave propagation on the string is

A) 127 m/s.

B) 198 m/s.

C) 210 m/s.

D) 273 m/s.

E) 305 m/s.

14) A string on a guitar is stretched between two points 35.0 cm apart with a tension of 65.0 N. The mass/length of the string is 0.00400 kg/m. The wavelength of the mode of vibration with the lowest frequency is

A) 0.5 m.

B) 0.6 m.

C) 0.7 m.

D) 0.8 m.

E) 0.9 m.

15) A string on a guitar is stretched between two points 35.0 cm apart with a tension of 65.0 N. The mass/length of the string is 0.00400 kg/m. The frequency of the mode of vibration with the lowest frequency is

A) 315 Hz.

B) 276 Hz.

C) 250 Hz.

D) 205 Hz.

E) 182 Hz.

16) A string on a guitar is stretched between two points 30.0 cm apart with a tension of 100 N. The mass/length of the string is 0.00300 kg/m. The velocity of wave propagation on the string is

A) 175 m/s.

B) 183 m/s.

C) 205 m/s.

D) 267 m/s.

E) 300 m/s.

17) A string on a guitar is stretched between two points 30.0 cm apart with a tension of 100 N. The mass/length of the string is 0.003 kg/m. The wavelength of the mode of vibration with the lowest frequency is

A) 0.3 m.

B) 0.4 m.

C) 0.5 m.

D) 0.6 m.

E) 0.7 m.

18) A string on a guitar is stretched between two points 30.0 cm apart with a tension of 100 N. The mass/length of the string is 0.00300 kg/m. The frequency of the mode of vibration with the lowest frequency is

A) 304 Hz.

B) 350 Hz.

C) 376 Hz.

D) 415 Hz.

E) 433 Hz.

19) A string on a violin is stretched between two points 20.0 cm apart with a tension of 120 N. The mass/length of the string is 0.00200 kg/m. The frequency of the mode of vibration with the lowest frequency is

A) 502 Hz.

B) 550 Hz.

C) 598 Hz.

D) 612 Hz.

E) 750 Hz.

20) A string on a violin is stretched between two points 20.00 cm apart with a tension of 120.0 N. The mass/length of the string is 0.002000 kg/m. The frequency of the mode next higher than the fundamental mode is

A) 1,400 Hz.

B) 1,322 Hz.

C) 1,225 Hz.

D) 1,558 Hz.

E) 2,120 Hz.

21) A string on a violin is stretched between two points 20.00 cm apart with a tension of 120.0 N. The mass/length of the string is 0.002000 kg/m. The frequency of the 2nd overtone is

A) 1,502 Hz.

B) 1,837 Hz.

C) 2,237 Hz.

D) 2,568 Hz.

E) 3,250 Hz.

22) Two strings on a violin are stretched between two points 20.0 cm apart. The mass per length of the strings are the same. If the ratio of the frequencies of the fundamental modes is 1.5 to 1.0, then what is the ratio of the tensions in the strings?

A) 1.22

B) 1.88

C) 1.00

D) 2.25

E) 1.50

23) Two strings on a violin are stretched between two points 20 cm apart. The tensions of the strings are the same. If the ratio of the frequencies of the fundamental modes is 1.5 to 1.0, then what is the ratio of the mass per lengths in the strings?

A) 0.44

B) 0.80

C) 0.85

D) 0.94

E) 0.78

24) A string with a mass/length of 0.00200 kg/m is stretched between two points with a tension of 120 N. If the fundamental frequency is 440 Hz, then what is the distance between the two points?

A) 17.5 cm

B) 20.3 cm

C) 27.8 cm

D) 30.0 cm

E) 35.0 cm

25) A string with a mass/length of 0.00200 kg/m is stretched between two points with a tension of 120 N. If the fundamental frequency is 660 Hz, then what is the distance between the two points?

A) 17.5 cm

B) 18.6 cm

C) 20.3 cm

D) 26.7 cm

E) 30.0 cm

26) A string with a mass/length of 0.00200 kg/m is stretched between two points with a tension of 115 N. If the distance between the points is changed by 1.0% (keeping the tension and mass per unit length the same), then what is the percentage change of the frequency?

A) 0.50%

B) 0.75%

C) 1.00%

D) 1.25%

E) 1.50%

27) The speed of waves in stretched string depends on which of the following?

A) the tension in the string

B) the amplitude of the waves

C) the wavelength of the waves

D) the frequency of the waves

28) Of these properties of waves, which one is independent of the others?

A) amplitude

B) period

C) frequency

D) wavelength

29) Visible light consists of electromagnetic waves with wavelengths (in air) in the range 400–700 nm. The speed of light in air is 3.0 × 108 m/s. What are the frequencies of visible light?

A) 1.33 × 1014 Hz to 2.33 × 1014 Hz

B) 1.33 × 1012 Hz to 2.33 × 1012 Hz

C) 4.29 × 1012 Hz to 7.50 × 1012 Hz

D) 4.29 × 1014 Hz to 7.50 × 1014 Hz

30) A transverse wave travels at 250 m/s along the z-axis. If the frequency of the periodic vibrations of the wave is 440 Hz, then what is the wavelength of the wave?

A) 21.9 cm

B) 26.7 cm

C) 35.7 cm

D) 56.8 cm

E) 73.7 cm

31) A transverse wave travels at 230.0 m/s along the y-axis. If the frequency of the periodic vibrations of the wave is 390.0 Hz, then what is the wavelength of the wave?

A) 58.97 cm

B) 47.23 cm

C) 40.89 cm

D) 36.76 cm

E) 68.97 cm

32) A transverse wave travels at 190 m/s along the x-axis. If the period of the periodic vibrations of the wave is 2.6 milliseconds, then what is the wavelength of the wave?

A) 25.5 cm

B) 35.4 cm

C) 49.4 cm

D) 50.3 cm

E) 54.4 cm

33) A wave travels at 175 m/s along the x-axis. If the period of the periodic vibrations of the wave is 3.00 milliseconds, then what is the wavelength of the wave?

A) 25.5 cm

B) 35.6 cm

C) 42.9 cm

D) 49.5 cm

E) 52.5 cm

34) The frequency of a periodic wave is 340 Hz. The period of the vibration motion of the wave is

A) 2.56 milliseconds.

B) 2.94 milliseconds.

C) 3.55 milliseconds.

D) 3.94 milliseconds.

E) 4.25 milliseconds.

35) The period of a periodic wave is 2.80 milliseconds. The frequency of the vibration motion of the wave is

A) 450 Hz.

B) 437 Hz.

C) 402 Hz.

D) 357 Hz.

E) 306 Hz.

36) The frequency of a periodic wave is 325 Hz. If the wavelength is 50.0 cm, then what is the velocity of the wave?

A) 163 m/s

B) 203 m/s

C) 237 m/s

D) 285 m/s

E) 316 m/s

37) The wavelength of a periodic wave is 0.750 m. If the frequency is 425 Hz, then what is the velocity of the wave?

A) 210 m/s

B) 276 m/s

C) 319 m/s

D) 410 m/s

E) 472 m/s

38) The wavelength of a periodic wave is 0.750 m. If the frequency is 425 Hz, then what is the angular frequency ω of the wave?

A) 5.44 × 103 rad/s

B) 5.03 × 103 rad/s

C) 4.21 × 103 rad/s

D) 3.76 × 103 rad/s

E) 2.67 × 103 rad/s

39) The wavelength of a periodic wave is 0.800 m. If the frequency is 400 Hz, then what is the wavenumber k of the wave?

A) 8.56 m−1

B) 7.85 m−1

C) 7.02 m−1

D) 6.35 m−1

E) 5.98 m−1

40) The wavelength of a periodic wave is 0.750 m. If the frequency is 365 Hz, then what is the angular frequency ω of the wave?

A) 3.87 × 103 rad/s

B) 3.10 × 103 rad/s

C) 2.98 × 103 rad/s

D) 2.29 × 103 rad/s

E) 1.75 × 103 rad/s

41) The wavelength of a periodic wave is 0.500 m. If the frequency is 400 Hz, then what is the wavenumber k of the wave?

A) 12.6 m−1

B) 14.8 m−1

C) 18.4 m−1

D) 21.0 m−1

E) 25.9 m−1

42) A longitudinal wave travels on a slinky or any long spring. The wave is represented by the equation x(x, t) = 2.1 cm cos(2000 rad/s t − 40 m−1 x). What is the direction of propagation of the wave?

A) the − x direction

B) the + x direction

C) the − y direction

D) the + y direction

43) A longitudinal wave travels on a slinky or any long spring. The wave is represented by the equation x(x, t) = 2.1 cm cos(2000 rad/s t − 40 m−1 x). What is the direction of motion of a point on the spring due to the wave?

A) the ± y direction

B) the ± z direction

C) the ± x direction

44) A longitudinal wave travels on a slinky or any long spring. The wave is represented by the equation x(x, t) = 2.10 cm cos(2000 rad/s t + 40.0 m−1 x). What is the velocity of the wave?

A) 50 m/s in the + x direction

B) 50 m/s in the − x direction

C) 0.02 m/s in the + x direction

D) 0.02 m/s in the − x direction

45) A longitudinal wave travels on a slinky or any long spring. The wave is represented by the equation z(z, t) = 1.2 cm cos(1800 rad/s t + 60 m−1 z). What are the wavenumber and direction of propagation of the wave?

A) 60 m−1; traveling in the + z direction

B) 60 m−1; traveling in the − z direction

C) 60 m−1; traveling in the + x direction

D) 60 m−1; traveling in the − x direction

46) A transverse periodic wave is represented by the equation y(x, t) = 2.50 cm cos(2,500 rad/s t − 15.0 m−1 x). What is the direction of the vibration of the wave?

A) the z direction

B) the y direction

C) the x direction

47) A transverse periodic wave is represented by the equation y(x, t) = 2.50 cm cos(2,500 rad/s t − 15.0 m−1 x). What is the direction of the velocity of the wave?

A) the + z direction

B) the + y direction

C) the + x direction

D) the − z direction

E) the − y direction

F) the − x direction

48) A transverse periodic wave is represented by the equation y(x, t) = 2.50 cm cos(2,500 rad/s t − 15.0 m−1 x). What is the velocity of the wave?

A) 450 m/s in the − y direction

B) 333 m/s in the + y direction

C) 333 m/s in the + x direction

D) 167 m/s in the − x direction

E) 167 m/s in the + x direction

49) A transverse periodic wave is represented by the equation y(x, t) = 2.50 cm cos(2,500 rad/s t − 15.0 m−1 x). What are the wavenumber k and direction of propagation of the wave?

A) 15.0 m−1; traveling in the − x direction

B) 15.0 m−1; traveling in the + x direction

C) 30.0 m−1; traveling in the + y direction

D) 30.0 m−1; traveling in the − y direction

E) 45.0 m−1; traveling in the + x direction

50) A transverse periodic wave is represented by the equation y(x, t) = 2.50 cm cos(2,500 rad/s t − 15.0 m−1 x). What is the frequency of the vibration of the wave?

A) 490 Hz

B) 467 Hz

C) 422 Hz

D) 398 Hz

E) 302 Hz

51) A transverse periodic wave is represented by the equation z(y, t) = 1.50 cm sin(1,250 rad/s t + 10.0 m−1 y). What is the direction of the vibration of the wave?

A) the x direction

B) the y direction

C) the z direction

52) A transverse periodic wave is represented by the equation z(y, t) = 1.50 cm sin(1,250 rad/s t + 10.0 m−1 y). What is the direction of the velocity of the wave?

A) the x direction

B) the y direction

C) the z direction

D) the t direction

53) A transverse periodic wave is represented by the equation z(y, t) = 1.50 cm sin(1,250 rad/s t + 10.0 m−1 y). What is the velocity of the wave?

A) 125 m/s in the + z direction

B) 250 m/s in the − z direction

C) 125 m/s in the + y direction

D) 125 m/s in the − y direction

E) 250 m/s in the − y direction

54) A transverse periodic wave is represented by the equation z(y, t) = 1.50 cm sin(1,250 rad/s t + 10.0 m−1 y). What are the wavenumber k and direction of propagation of the wave?

A) 10 m−1; traveling in the + y direction

B) 10 m−1; traveling in the − y direction

C) 20 m−1; traveling in the + z direction

D) 20 m−1; traveling in the − z direction

E) 10 m−1; traveling in the − z direction

55) A transverse periodic wave is represented by the equation z(y, t) = 1.50 cm sin(1,250 rad/s t + 10.0 m−1 y). What is the frequency of the vibration of the wave?

A) 319 Hz

B) 289 Hz

C) 240 Hz

D) 199 Hz

E) 150 Hz

56) A transverse periodic wave is represented by the equation y(x, t) = 1.50 cm sin(1,500 rad/s t − 10.0 m−1 x). Another transverse wave is represented by the equation y(x, t) = 1.50 cm sin(1,500 rad/s t − 10.0 m−1 x). What is the equation that represents the superposition of the two waves?

A) y(x, t) = 3.0 cm sin(1,500 rad/s t − 10.0 m−1 x)

B) y(x, t) = 3.0 cm sin(1,500 rad/s t) cos(10.0 m−1 x)

C) y(x, t) = 3.0 cm cos(1,500 rad/s t) sin(10.0 m−1 x)

D) y(x, t) = 3.0 cm sin(1,500 rad/s t + 10.0 m−1 x)

57) A transverse periodic wave is represented by the equation y(x, t) = 1.50 cm sin(1,500 rad/s t − 10.0 m−1 x). Another transverse wave is represented by the equation y(x, t) = 1.50 cm sin(1,500 rad/s t + 10.0 m−1 x). What is the equation that represents the superposition of the two waves?

A) y(x, t) = 3.0 cm sin(1,500 rad/s t − 10.0 m−1 x)

B) y(x, t) = 3.0 cm sin(1,500 rad/s t) cos(10.0 m−1 x)

C) y(x, t) = 3.0 cm cos(1,500 rad/s t) sin(10.0 m−1 x)

D) y(x, t) = 3.0 cm sin(1,500 rad/s t + 10.0 m−1 x)

58) A transverse periodic wave is represented by the equation y(x, t) = −1.50 cm sin(1,500 rad/s t − 10.0 m−1 x). Another transverse wave is represented by the equation y(x, t) = +1.50 cm sin(1,500 rad/s t + 10.0 m−1 x). What is the equation that represents the superposition of the two waves?

A) y(x, t) = 3.0 cm sin(1,500 rad/s t − 10.0 m−1 x)

B) y(x, t) = 3.0 cm sin(1,500 rad/s t) cos(10.0 m−1 x)

C) y(x, t) = 3.0 cm cos(1,500 rad/s t) sin(10.0 m−1 x)

D) y(x, t) = 3.0 cm sin(1,500 rad/s t + 10.0 m−1 x)

59) A transverse periodic wave is represented by the equation y(x, t) = A1 sin(ωt − kx). Another transverse wave is represented by the equation y(x, t) = A2 sin(ωt + kx). What is the equation that represents the superposition of the two waves?

A) y(x, t) = (A1 + A2) sin(ωt) cos(kx) + (+A1 + A2) cos(ωt) sin(kx)

B) y(x, t) = (A1 + A2) sin(ωt) cos(kx) + (−A1 − A2) cos(ωt) sin(kx)

C) y(x, t) = (A1 − A2) sin(ωt) cos(kx) + (−A1 + A2) cos(ωt) sin(kx)

D) y(x, t) = (A1 + A2) sin(ωt) cos(kx) + (−A1 + A2) cos(ωt) sin(kx)

60) A transverse periodic wave is represented by the equation y(z, t) = 2.0 cm sin(1,200 rad/s t − 20.0 m−1 z). Another transverse wave is represented by the equation y(z, t) = 2.0 cm sin(1,200 rad/s t − 20.0 m−1 z). What is the equation that represents the superposition of the two waves?

A) y(z, t) = 4.0 cm sin(1,200 rad/s t − 20.0 m−1 z)

B) y(x, t) = 4.0 cm sin(1,200 rad/s t) cos(20.0 m−1 x)

C) y(x, t) = 4.0 cm cos(1,200 rad/s t) sin(20.0 m−1 x)

D) y(x, t) = 4.0 cm cos(1,200 rad/s t + 20.0 m−1 x)

61) A transverse periodic wave is represented by the equation y(z, t) = 2.0 cm sin(1,200 rad/s t − 20.0 m−1 z). Another transverse wave is represented by the equation y(z, t) = 2.0 cm sin(1,200 rad/s t + 20.0 m−1 z). What is the equation that represents the superposition of the two waves?

A) y(z, t) = 4.0 cm sin(1,200 rad/s t − 20.0 m−1 z)

B) y(x, t) = 4.0 cm sin(1,200 rad/s t) cos(20.0 m−1 x)

C) y(x, t) = 4.0 cm cos(1,200 rad/s t) sin(20.0 m−1 x)

D) y(x, t) = 4.0 cm cos(1,200 rad/s t + 20.0 m−1 x)

62) A transverse periodic wave is represented by the equation y(z, t) = −2.0 cm sin(1,200 rad/s t − 20.0 m−1 x). Another transverse wave is represented by the equation y(z, t) = +2.0 cm sin(1,200 rad/s t + 20.0 m−1 z). What is the equation that represents the superposition of the two waves?

A) y(z, t) = 4.0 cm sin(1,200 rad/s t − 20.0 m−1 z)

B) y(x, t) = 4.0 cm sin(1,200 rad/s t) cos (20.0 m−1 x)

C) y(x, t) = 4.0 cm cos(1,200 rad/s t) sin (20.0 m−1 x)

D) y(x, t) = 4.0 cm cos(1,200 rad/s t + 20.0 m−1 x)

63) The following figure is a graph of a wave at a fixed position.

The following figure is a graph of the same wave at a fixed time.

What is the velocity of the wave in the above figure?

A) 150 m/s

B) 200 m/s

C) 250 m/s

D) 300 m/s

E) 450 m/s

64) What is the frequency of the wave?

A) 80 Hz

B) 50 Hz

C) 120 Hz

D) 140 Hz

E) 160 Hz

65) A wave is represented by the equation y(x, t) = 3.2 cm sin(1000 rad/s t − 50 m−1 x). Another wave, with the same wavelength and frequency, has an amplitude of 4.2 cm. If the two waves interfere constructively, then which equation could represent the superposition of the two waves?

A) y(x, t) = 7.4 cm sin(1000 rad/s t + 50.0 m−1 x)

B) y(x, t) = 1.0 cm sin(1000 rad/s t − 50.0 m−1 x)

C) y(x, t) = 1.0 cm sin(1000 rad/s t + 50.0 m−1 x)

D) y(x, t) = 7.4 cm sin(1000 rad/s t − 50.0 m−1 x)

66) A wave is represented by the equation y(x, t) = 3.2 cm sin(1000 rad/s t − 50 m−1 x). Another wave, with the same wavelength and frequency, has an amplitude of 4.2 cm. If the two waves interfere destructively, then which equation could represent the superposition of the two waves?

A) y(x, t) = 7.4 cm sin(1000 rad/s t + 50.0 m−1 x)

B) y(x, t) = 1.0 cm sin(1000 rad/s t − 50.0 m−1 x)

C) y(x, t) = 1.0 cm sin(1000 rad/s t + 50.0 m−1 x)

D) y(x, t) = 7.4 cm sin(1000 rad/s t − 50.0 m−1 x)

67) A wave is traveling with a velocity of 300 m/s and strikes a surface at an angle of 30.0 degrees with the normal to the surface. The wave splits into a reflected part and a refracted part. The refracted wave travels with a velocity of 400 m/s. What is the angle of refraction?

A) 20.5 degrees

B) 25.9 degrees

C) 30.5 degrees

D) 41.8 degrees

E) 50.3 degrees

68) A wave is traveling with a velocity of 350 m/s and strikes a surface at an angle of 30.0 degrees with the normal to the surface. The wave splits into a reflected part and a refracted part. The refracted wave travels with a velocity of 300 m/s. What is the angle of refraction?

A) 50.4 degrees

B) 45.2 degrees

C) 40.4 degrees

D) 38.4 degrees

E) 25.4 degrees

69) A longitudinal wave is represented by the equation z(z, t) = −2.0 cm sin(1,200 rad/s t − 20 m−1 z). Another longitudinal wave is represented by the equation z(z, t) = +2.0 cm sin(1,200 rad/s t + 20 m−1 z). What is the equation that represents the superposition of the two waves?

A) z(z, t) = -4.0 cm cos(1,200 rad/s t) sin(20 m−1 z) 

B) z(z, t) = +4.0 cm cos(1,200 rad/s t) sin(20 m−1 z)

C) z(z, t) = +4.0 cm cos(1,200 rad/s t) cos(20 m−1 z)

D) z(z, t) = −2.0 cm cos(1,200 rad/s t) sin(20 m−1 z)

70) When light traveling in air passes into a sheet of glass, it is observed to change in wavelength to 58% of its wavelength in air. The speed of light in air is 3.0 × 108 m/s. What is the speed of light in the glass?

A) 5.2 × 108 m/s

B) 1.7 × 108 m/s

C) 3.0 × 108 m/s

D) 2.3 × 108 m/s

71) The speed of sound in air is dependent upon the air temperature and other factors. The speed of sound increases from 334 m/s to 341 m/s between 8:00am and 11:00am. If a horn produces sound with wavelength 0.75 m at 8:00am, what would it produce at 11:00am, assuming the frequency is unchanged?

A) 73 cm

B) 77 cm

C) Not enough info given to solve.

D) 75 cm

72) Two speakers are emitting coherent sound waves at a frequency of 440 Hz. The waves are emitted in phase. If the speed of sound is 343 m/s, and it is observed that no sound is heard 17.2 m from one speaker, which of the following is a possible distance to the second speaker?

A) 14.5 m

B) 17.2 m

C) 19.6 m

D) 18.8 m

E) 16.5 m

F) 18.0 m

73) Two speakers, facing each other, produce coherent sound waves that interfere destructively at a point that is ¾ of the way from one speaker to the other. If the speed of sound is 343 m/s, and the sound waves are emitted in phase at 880 Hz, which of the following is a possible distance between the two speakers?

A) 2.7 m

B) 0.58 m

C) 1.56 m

D) 2.3 m

E) 77 cm

74) Two speakers are driven exactly out of phase with each other at 256 Hz. If a microphone placed on the line between the two speakers, exactly in the middle, detects no sound at all, then what is possibly the distance between the microphone and each speaker? The speed of sound is 340 m/s.

A) 0.75 m

B) 0.38 m

C) Can be any distance at all

D) 1.50 m

E) 0.94 m

75) A pair of speakers emits coherent sound waves in phase at a frequency of 440 Hz. A microphone is placed such that it is 1.0 m from one speaker on a line that is perpendicular to the line between the speakers. Which of the following distances reflects a possible distance between the speakers if there is complete destructive interference at the location of the microphone? The speed of sound is 340 m/s.

A) 1.0 m

B) 0.77 m

C) 2.76 m

D) 1.3 m

E) 1.77 m

76) A microphone records sound produced from two speakers. As the microphone is moved around, a position at which the microphone receives a minimum intensity is found. If the intensity of one of the sound waves alone at that location is 0.055 W/m2, and if the microphone receives an intensity of 0.004 W/m2 there, what is a possible value for the intensity of the other source at the microphone's location?

A) Need more info to solve.

B) 0.089 W/m2

C) 0.051 W/m2

D) 0.048 W/m2

77) Two speakers emit incoherent sound waves into the open air. One of them produces 75W of power. A microphone is placed at a position that is 12m from each speakers, and it receives a total intensity of 0.25W/m2. What is the power output of the second speaker?

A) 151 W

B) 377 W

C) Need more info to solve.

D) 38 W

78) A cello plays a note of frequency 220 Hz using a length L of one of its strings. What length of the same string must be used in order to play a fundamental frequency of 256 Hz? Assume in each case that the note played is the fundamental frequency of the string at the given length and that the tension T and mass per unit length are not changed when selecting a different length of the same string.

A) 0.86L

B) 1.72L

C) 0.58L

D) 1.16L

E) 0.43L

F) 2.32L

79) A guitar string is supposed to be played with a fundamental frequency of 880 Hz. If it is determined to have, instead, a fundamental frequency of 882 Hz, by what amount (as a percentage) must the tension in the string be changed in order that the fundamental frequency be restored to 880 Hz?

A) −0.45%

B) +0.45%

C) −0.11%

D) −0.23%

80) What is the mass of a string that is 17 cm long and has a fundamental frequency of 792 Hz when under a tension of 1.7 kN?

A) 4.0 g

B) 64 g

C) 1.6 g

D) 32 g

E) 6.4 g

F) 3.2 g

81) A length of piano wire is used to hang a mass from the ceiling. If the total mass of the string is 0.72 g and the mass hung from it is 1850 g, what is the length of the wire, assuming the fundamental frequency when plucked in these circumstances is 320 Hz?

A) 2.48 cm

B) 6.15 cm

C) 3.08 cm

D) 1.54 cm

82) A guitar string has a tension of 95 N and is 75 cm long. If its mass is 0.27 g, what is the frequency of the first resonance above the fundamental?

A) 685 Hz

B) 69 Hz

C) 217 Hz

D) 470 kHz

83) What is the mass of a 1.25 m long piano wire that has a fundamental frequency of 256 Hz when under a tension of 552 N?

A) 6.4 g

B) 1.7 g

C) 3.4 g

D) 41 g

E) 4.1 g

84) Two guitar strings are under the same tension and have the same length. If their fundamental frequencies are in a ratio of 3:2, what is the ratio of their masses?

A) 3/2

B) 2/3

C) 9/4

D) 4/9

85) A sound wave radiates from a source uniformly in all directions. If the power of the sound source is 200 watts, then the intensity of the sound wave 100 m from the source is

A) 2.2 mW/m2.

B) 2.0 mW/m2.

C) 1.8 mW/m2.

D) 1.6 mW/m2.

E) 1.2 mW/m2.

86) The speed of sound in water is 4.3 times the speed of sound in air. A whistle produces a sound wave in air with a frequency f0. When this sound wave enters the water, its frequency will be

A) 4.3 f0.

B) f0.

C) f0/4.3.

D) not enough information

87) A string with a mass per length of 2.00 g/m is stretched between two points that are 0.400 m apart. The frequency of the second mode of the stretched string is 50.0 Hz lower than the frequency of the third mode. What is the tension in the string?

A) 281 N

B) 101 N

C) 3.20 N

D) 2.26 N

E) 1.60 N

88) A string with a mass per length of 2.00 g/m is stretched between two points that are 0.400 m apart. The frequency of the third mode of the stretched string is 20.0 Hz lower than the frequency of the fourth mode. What is the tension in the string?

A) 180 N

B) 64.8 N

C) 2.05 N

D) 1.45 N

E) 0.064 N

89) A string with a mass per length of 2.00 g/m is stretched between two points that are 0.400 m apart. The frequency of the third mode of the stretched string is 120 Hz higher than the frequency of the fundamental. What is the tension in the string?

A) 2.30 N

B) 3.26 N

C) 4.61 N

D) 18.4 N

E) 101 N

90) Two piano strings are simultaneously played—their mass and length are identical, but the tensions differ. If the first string resonates with a fundamental frequency of 330 Hz, and its tension is 1.2% greater than that of the second string, what is the fundamental frequency of the second string?

A) 328 Hz

B) 326 Hz

C) 336 Hz

D) 334 Hz