Sound and Wave Test Review
1. If two wave pulses traveling on the same side of the
wave crossover, what type of interference will occur?
ans: constructive
2. Two wave pulses travel toward each other on opposite
sides of the wave crossover. Both pulses measure at 2 cm.
What is the size of the wave at the point of crossover?
ans: zero
3. What type of wave interference occurs in #2?
ans: destructive
4. A pulse traveling east is displaced by 3 cm
while another pulse travels west. At the point of
crossover the displacement pulse is measured to
5 cm. What is the displacement of the pulse that
is traveling to the west?
ans: 2 cm
5. What type of interference occurs in #4?
and constructive
6. When does the cancellation of the wave pulse
occur?
ans: when the pulses are on opposite sides
and at the point of crossover
7. Frequency is the cycles/s. This means that the
period is ____________?
ans: s / cycle
8. In the pendulum lab, if the rubber stop swung
15 time in 5 s, the frequency is __________.
ans: 3 cycles / s
9. In the pendulum lab, the rubber stopper swung
10 times in 5 s, what is the period?
ans: 0.5 s / cycle
10. On a rainy day, you watch the rain drip off the
edge of the window. If you count 3 drop each 2
seconds and the speed of a drop is 2.45 m/s,
what is the distance between each drop?
ans: 1.633 m between drops
11. With a water wave, if you increase the time
you slap the water for 10/s to 20/s, the
wavelength of the wave generated would ____?
ans: decrease the wavelength
12. Draw the wave pulse at the point of
crossover?
3cm
5cm
13. What is the speed of a wave that has a
wavelength of 2.5 cm and vibrates at a period of
4 s/cycle?
ans: 0.625 cm/s
14. The position on a wave that show the energy
supplied is equal to the energy of the wave is
called the______?
ans: node
15. A sound has a frequency of 205 800 Hz and a
wavelength of 0.025 m. What is the speed of this
wave?
ans: 5145 m/s
16. If the speed of sound in the air is 343 m/s,
through what medium would you guess the
sound is traveling in #15?
ans: solids, 15x faster
17. A wave pulse travels down a string tied to a
wall. Describe the wave behavior as the pulse
strikes the wall.
ans: reversed and flipped
18. How many wave segments are there is a
single wavelength?
ans: 4
19. Whole number multiples of the frequency of
a wave is called ____________?
ans: harmonics
20. What type of wave is composed of a series of
compressions and rarefraction?
ans: Longnitudual wave
21. If the pitch increases, then the wavelength __
ans: decrease
22. If the pitch increases, then the speed of sound
at the same temperature and pressure will?
ans: remain the same
23. Loudness makes the speed of the sound
wave increase?
ans: False
24. In an open-ended resonator that is 0.5 m
long, what is the frequency at the 1st harmonic at
20oC?
ans: 343 Hz
25. In a closed-ended resonator that is 0.5 m
long, what is the frequency at the 1st harmonic at
20oC?
ans: 171.5 Hz
26. Compare #24 and #25. Which tube would
have the higher pitch?
ans: 343 Hz , #24.
27. What is the period of a pendulum if the
length of the pendulum is 34.8 m?
ans: 11.8 s
28. What is the period in #27 affected with the
length of the pendulum is decreased?
ans: decrease the period
29. How is the period of the pendulum in #27
affected with an increase in mass?
ans: no change.
30. The reflection of a sound wave off a hard
surface is called a(n) _______?
ans: echo
31. If it take 5 s for you to hear your echo, how
fast is the sound traveling at 20oC ?
ans: 343 m/s constant
32. How far is the reflective surface in #31?
ans: 857.5 m
33. A sound source has a frequency of 750 Hz is
moving at 45 m/s toward a sound meter setting
at rest. What is the apparent shift in frequency
detected by the meter?
ans: 863.3 Hz
34. What is the apparent shift in frequency as the
sound source in #33 move away from the
meter?
ans: 663 Hz
35. What part of the human ear transfers
impulses to the brain?
ans: nerve hairs in the cochlea
36. What is the standard speed of sound at
20oC at sea level?
ans 343 m/s
37. At sea level, what is the speed of sound at
25oC?
ans: 331 m/s + (0.6 x 25oC) = 346 m/s
38. When two different objects vibrate at the
same frequency, they are said to be in:
ans: resonance
39. What type of resonator is open at both
ends?
ans: open ended resonator
40. In a sound lab, what is the relationship
between the vibrating tuning fork and the
vibrating air inside the tube?
ans: directly proportional
41. The vocal code vibrate to product speech.
42. What type of resonator is claosed at one
end?
ans: closed ended resonator
43. Putting together wave frequencies in
whole number multiples is called:
ans: harmonics
44. A chord that is pleasant to hear,
ans: consonance
45. The standard unit for frequency is
ans: Hertz, Hz or cycle/second
46. The difference in the frequency of two
waves is called the
ans: beat
47. Tone color and sound quality is the same
name for:
ans timbre
48. Two tuning forks one 393 Hz and other 423
Hz, what is the beat
ans: (fa – fb) ; (423 Hz – 393 Hz ) = 30 Hz
49. Open ended resonator @ 25oC , 1.25 m.
ans: f = v/2L = 346 m/s / (2*1.25) = 138.4 Hz
50. Closed ended @ 25oC, 1.25 m
ans: f = v/4L = 346 m/s / (4*1.25) = 69.2 Hz
51. What is the speed of a wave in iron rod
with f = 3500 Hz , 0.25 m long?
ans: v = λf : v = .25m(3500/s) = 875 m/s
52. A speed at 900 m/s and f = 450 Hz
ans: v = λf ; λ = 900 m/s / 450/s = 2 m
53. Closed ended. @18 cm and 3.2 m ?
ans: @ 0.18 m f = v/4L; 343 m/s / (4*.18) =
476.4 Hz
@ 3.2 m f = v/4L; 343 m/s / (4*3.2m) = 26.8 Hz
54.Velocity at 20oC = 343 m/s
55. An apparent change in the frequency is
ans: Doppler Effect
56. What type of wave is a sound wave?
ans: longitudual
57. How much faster does sound travel in
solid co,pared to air at 20oC ?
ans: 15x
58. How is sound measured?
ans: decibels, db
59. What is the lowest frequency heard by the
human ear?
ans: 20 Hz
60. What is the smallest λ detected by the
ear?
ans: 17.2 m
61. Frequency is to pitch as amplitude is to
ans: loudness
62. As pitch decreases:
frequency : decrease
speed: unchanged at the same temp
wavelength: increase
loudness: decrease