Name: ~
Test Chapter 12 (Sound)
Period Date:
Honors Physics Burns
/2010
Multiple Choice: Identify the choice that best completes the statement or answers the question. / ~./~ t~~ ~
1.
Sound waves a. are a part of the electromagnetic spectrum.
b, do not require a medium for transmission.
~ are longitudinal waves.
are transverse waves.
2.
The trough of the sine curve used to represent a sound wave con’esponds to a¯ a compression, c. the amplitude.
b. the wavelength.
~ a rarefaction.
3.
Which of the following is the region of a sound wave in which the density and pressure are greater than normal?
a. rarefaction
Q~ compression c. amplitude d. wavelength
4.
The highness or lowness of a sound is perceived as a. compression, c¯ ultrasound.
b. wavelength.
(~ pitch.
Pitch depends on the __ of a sound wave.
frequency c. power amplitude d¯ speed
6.
Of the following nlaterials, sound waves travel fastest through
,~. helium at 0°C.
~. copper at 0°C.
0. airat0°C, d. air at l00°C.
.~gOa
7.
In general, sound travels faster through lids than through gases, ses than through solids¯ c. gases than through liquids¯ d. empty space than through matter.
~.’)//At a large distance from a sound source, spherical wave fronts are viewed as
~’ "~ ~" U’a.~wavelengths.
~/L~/. ~taughs.
9. 9. A train moves down the track t~Wa~2d~an observer. The sound from the train, as heard by the observer, is __ the sound heard by a passenger on the train.
a. the same as ~)%igher in pitch than b. a different timbre than d. lower in pitch thma
10. ~1~ If you are on a train, how will the pitch of the train’s whistle sound to you as the train moves?
a. The pitch will become steadily higher.
b. The pitch will become steadily lower.
O The pitch will not change.
d. The pitch will become higher, then become lower.
11.
If the intensity of a sound is !ncreased by a factor of 100, the new decibel level will increase a. by two units.
,c. by a factor of 10.
(~ t? twice the old one.
d. by 20 units.
.2.
A sound twice the intensity of 60 d~s ~ba~g~a how inany decibels?
¯ 63dB d. 120dB

13. When the frequency of a force applied to a system matches the natural frequency of vibration of the system, __ occurs.
a. damped vibration b. random vibration c. timbre
(/~ resonance
’,4. For a standing wave in an air column in a pii~that is open at both ends, there must be a~t least a. one node and one antinode. ~,~ two antinodes and one node. ~ ..........
two nodes and one antinode. ~. two nodes and two antinodes. .
15. If a guitar string has a fundamental frequency of 500 Hz, what is the frequency of its second harmonic?
a. 250 Hz b. 750Hz
Qc.,~) 1000 d. 2000Hz t6. The quality of a musical tone of a certain pitch results from a combination of a. fundamental frequencies, c. transverse waves.
~’1~. harmo~i~s.~ d. velocities.
17. Musical instruments of different types playing the same note may often be identified by the __ of their sounds.
a. pitch b, intensity c. fundamental frequency
~ ~y~ -F~
18. How many beats per second are heard when two vibrating tuning forks having frequencies of 216 Hz and 224 Hz are held side by side?
a, 6 Hz
~i~ff~’:z~
c. 9 Hz d. 3 Hz
19.
A vibrating guitar string emits a tone just as a 5.00 x l(0~clz tuning fork is struck. If five beats per second are heard, which of the following is a possible frequency of vibration of the string?
~, 2500Hz’
~. 1500Hz c. 605Hz
~ d. 495 Hz
(a)
(b)
20. In the figure shown above, a beat occurs at a. t.g c.
d. t!and ~

Problem Solving: SHOW ALL WORK!
An engineer at an underwater military station listens for submarines by sending an ultrasound sonar ping that has a frequency of 3.75 MHz. [~ PO a. A stationary object is detected when the ping returns 3.00 s later. How far away is this object? The speed of sound in seawater is 1533 m!s.
--d b. A second ping returns with a frequency of 3.80 MHz, indicating that the object is now moving.station? Whatf/is the= object’s,~ ~~vel°citY?v -~. V ~In/which direction/is it moving relative to the listening@
Sonar equipment has difficulty detecting objects smaller than the wavelength of the ping. Old sonar equipment used an audible ping with a frequency of 400 Hz. What is the smallest ,~’~ object this old sonar could distinguish?

A train whistle has a fundamental frequency of 880 Hz and a wavelength of 0.384 m.
What is the speed of this sound in air?
b. What temperature is the air?
c. If the whistle is a closed pipe, then how long is it?
o,3~ -
)
If the next harmonic were to be heard in the closed pipe, how long would the pipe have to @
1’~ ........................... ’/ /
3. A 00-Hz tone must have what sound level to seem as loud as a~0-Hz tone that has a 50-dB sound level? Briefly explain why this is so, referring to the graph in your explanation,

4.
A physics teacher sets up a 0.92 m long open tube to resonate at its fundamental frequency.
Draw a diagram of the standing wave in the tube.
b. What is the wavelength of the wave if room temperature is 27.3°?
c. What is the fundamental frequency of the sound?
What is the fifth overtone in the open tube?
5. A boy drops a stone offofa cliff. If it takes 2.4 s until the sound of the splash is heard, how @ high is the cliff?. ~ "~ ~ 3 ~/3 ~ ~-,~,~o£ ~’2 ~’~"~÷g~