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Scott, MIT Graduate
Category: Homework
Satisfied Customers: 3040
Experience:  MIT Graduate (Math, Programming, Science, and Music)
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1. In which one of the following locations can a person

Customer Question

1.   In which one of the following locations can a person hear the echo of a sound?

     A. At least 33.2 meters behind the reflecting surface
     B. Less than 16.6 meters in front of the reflecting surface

     C. Less than 33.2 meters behind the reflecting surface

     D. At least 16.6 meters in front of the reflecting surface

2.   In a transverse wave that travels through a medium, the molecules of the medium vibrate

     A. at twice the velocity of the molecules in a longitudinal wave.
     B. at right angles to the direction in which the wave travels.

     C. with smaller amplitudes than the molecules in a longitudinal wave.

     D. in the direction in which the wave travels.

3.   If you were trying to build a soundproof room, which of the following materials would you choose in order to absorb the most sound?

     A. Heavy curtains
     B. Concrete

     C. Wood

     D. Carpet

4.   If a wave hits a smooth surface at an angle of incidence of 40 degrees, the angle of reflection is

     A. 80 degrees.
     B. 0 degrees.

     C. 40 degrees.

     D. 90 degrees.

5.   Through which one of the following mediums is the velocity of a sound wave the greatest?

     A. Air
     B. Steel

     C. Lead

     D. Water

6.   A wave front has the form of a

     A. surface of a sphere.
     B. straight line.

     C. sine wave.

     D. circle.

7.   The spreading of sound waves around openings in barriers is called

     A. reverberation.
     B. refraction.

     C. an echo.

     D. diffraction.

8.   When a tuning fork vibrates over an open pipe and the air in the pipe starts to vibrate, the vibrations in the tube are caused by

     A. beats.
     B. reinforcement.

     C. resonance.

     D. harmonics.

9.   The wavelength of a wave is the distance between

     A. the rarefaction and the following compression.
     B. the amplitude and the normal position.

     C. two consecutive crests.

     D. the crest and the following trough.

10.   A surface receiving sound is moved from its original position to a position three times farther away from the source of the sound. The intensity of the received sound thus becomes

     A. three times as high.
     B. nine times as high.

     C. nine times as low.

     D. three times as low.

11.   The number of waves that pass a particular point in a body in a unit of time is called the _______ of the waves.

     A. rarefaction
     B. compression

     C. frequency

     D. amplitude

12.   In a stringed musical instrument, the part that vibrates in resonance with the sound waves produced by the strings is called the

     A. sounding board.
     B. diatonic scale.

     C. membrane.

     D. reed.

13.   Which one of the following frequencies of a wave in the air can be heard as an audible sound by the human ear?

     A. 1,000 Hz
     B. 0.10 Hz

     C. 10 Hz

     D. 100,000 Hz

14.   The part of the ear where sound wave compressions and rarefactions cause the eardrum to vibrate is the

     A. middle ear.
     B. inner ear.

     C. auditory nerve.

     D. outer ear.

15.   When the temperature of the air is 25°C, the velocity of a sound wave traveling through the air is approximately

     A. 347 m/s.
     B. 357 m/s.

     C. 320 m/s.

     D. 332 m/s.

16.   In a stringed musical instrument, the sound frequency of a particular string can be increased by

     A. tightening the string.
     B. increasing the string's thickness.

     C. loosening the string.

     D. lengthening the string.

17.   The change in pitch of a train's horn as it passes while you are standing still can be explained by

     A. ultrasonic vibrations.
     B. the Doppler effect.

     C. resonance.

     D. sympathetic vibration.

18.   A wave with a period of 0.008 second has a frequency of

     A. 12.5 Hz.
     B. 800 Hz.

     C. 80 Hz.

     D. 125 Hz.

19.   If a source of sound waves is rapidly approaching a person, the sound heard by the person appears to have

     A. a period higher than the original period.
     B. an amplitude lower than the original amplitude.

     C. a frequency higher than the original frequency.

     D. a pitch lower than the original pitch.

20.   When a sound from a source is refracted away from the surface of the earth, it gives an indication that the

     A. air has high humidity.
     B. wind is blowing in the direction of the sound.

     C. ground is cooling faster than the air.

     D. air is cooler than the ground.

21.   The function of the eardrum in the middle ear is to

     A. carry the sound energy to the brain.
     B. collect the sound waves.

     C. amplify the received sound.

     D. vibrate with the frequency of the received sound.

22.   The maximum distance a molecule has been moved from its normal position by a wave is

     A. frequency.
     B. rarefaction.

     C. compression.

     D. amplitude.

23.   If a string vibrates at the fundamental frequency of 528 Hz and also produces an overtone with a frequency of 1,056 Hz, this overtone is the

     A. first harmonic.
     B. third harmonic.

     C. second harmonic.

     D. fourth harmonic.

24.   If a person is in front of a smooth surface from which a sound is reflected, the person would hear a sound that

     A. seems to come from behind the surface.
     B. seems to lack overtones.

     C. has a higher pitch than the sound produced by the source.

     D. has a higher intensity than the sound produced by the source.

25.   Rarefaction occurs only in a _______ wave.

     A. longitudinal.
     B. forced.

     C. transverse.

     D. sympathetic.
Submitted: 8 years ago.
Category: Homework

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