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: constructive2. 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: destructive4. 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 cm5. 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 crossover7. Frequency is the cycles/s. This means that the period is ____________?

ans: s / cycle8. 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 / cycle10. 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 drops11. 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?

3cm5cm

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: node15. 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/s16. 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 flipped18.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 wave21. If the pitch increases, then the wavelength __

ans: decrease22. 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: False24. In an open-ended resonator that is 0.5 m long, what is the frequency at the 1st harmonic at 20oC?

ans: 343 Hz25. 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 s28. 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: echo31. If it take 5 s for you to hear your echo, how fast is the sound traveling at 20oC ?

ans: 343 m/s constant32. 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 Hz34. 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 cochlea36. What is the standard speed of sound at 20oC at sea level?

ans 343 m/s37. 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: resonance39. What type of resonator is open at both ends?

ans: open ended resonator40. 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 resonator43. Putting together wave frequencies in whole number multiples is called:

ans: harmonics44. A chord that is pleasant to hear,

ans: consonance

45. The standard unit for frequency isans: Hertz, Hz or cycle/second

46. The difference in the frequency of two waves is called the

ans: beat47. Tone color and sound quality is the same name for:

ans timbre48. 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 Hz50. Closed ended @ 25oC, 1.25 mans: f = v/4L = 346 m/s / (4*1.25) = 69.2 Hz51. 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/s52. A speed at 900 m/s and f = 450 Hzans: 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 Hz54. Velocity at 20oC = 343 m/s55. An apparent change in the frequency is

ans: Doppler Effect56. 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: 15x58. How is sound measured?

ans: decibels, db59. What is the lowest frequency heard by the human ear?

ans: 20 Hz60. What is the smallest λ detected by the ear?

ans: 17.2 m

61. Frequency is to pitch as amplitude is to

ans: loudness62. As pitch decreases:

frequency : decreasespeed: unchanged at the same

tempwavelength: increaseloudness: decrease