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: 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: 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 Hz and a wavelength of 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: 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 1 st harmonic at 20 o C? ans: 343 Hz 25. In a closed-ended resonator that is 0.5 m long, what is the frequency at the 1 st harmonic at 20 o C? ans: Hz

26. Compare #24 and #25. Which tube would have the higher pitch? ans: 343 Hz, # 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 20 o C ? ans: 343 m/s constant 32. How far is the reflective surface in #31? ans: 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: 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 20 o C at sea level? ans 343 m/s 37. At sea level, what is the speed of sound at 25 o C? ans: 331 m/s + (0.6 x 25 o C) = 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 25oC, 1.25 m. ans: f = v/2L = 346 m/s / (2*1.25) = Hz 50. Closed 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 cm and 3.2 m ? 0.18 m f = v/4L; 343 m/s / (4*.18) = 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