Physics 011
A of
PQ#12A
Chapter
12 : Sound
Practice Questions


1. 

What are
the units for Intensity? Review Section 122 in Giancoli. 


2. 

What are
the units of Intensity Level? 


3. 

What are
the units of power? 


4. 

If 10^{n}=a
then log_{10}(a)=n, if e^{n}=a then log_{e}(a)=n
(e=2.17...). Use this to find the answer to this question. What is the log_{2}(16)? Review Appendix A9 in Giancoli. 


5. 

If 10^{n}=a
then log_{10}(a)=n, if e^{n}=a then log_{e}(a)=n
(e=2.17...). Use this to find the answer to this question. What is the Log_{3}(9)? 


6. 

If 10^{n}=a
then log_{10}(a)=n, if e^{n}=a then log_{e}(a)=n
(e=2.17...). Use this to find the answer to this question. What is the Log_{4}(2)? Review Appendix A9 in Giancoli. 


7. 

Log(2)+Log(3)= Review Appendix A9 in Giancoli. 


8. 

Log(2)Log(3)= Review Appendix A9 in Giancoli. 


9. 

The Log(3^{5})= 


10. 

What is
the speed of sound if the temperature is 10 degrees Celsius? This is the speed of light. Review Section 121 in Giancoli. 


11. 

If the
speed of sound is 350 m/s and the wavelength is 10 cm, what is the frequency? Review Example 127 in Giancoli. 


12. 

On a clear
winter day the speed of sound at ground level is The ground will be colder than the upper air. Review Section 121 in Giancoli. 


13. 

The
intensity level of one sound is 5 dB above another one. The ratio of the
intensity of the first to the second is Review Example 123 in Giancoli. 


14. 

The
intensity of one sound is 5 times the intensity of the second. What is the
difference in the intensity level? Review Example 123 in Giancoli. 


15. 

If you
were to inhale a few breaths from a helium gas balloon, you would probably
experience an amusing change in your voice. You would sound like Donald Duck
or Alvin the Chipmunk. What is the cause of this curious highpitched effect?
Review Section 122 in Giancoli. 


16. 

A police
car has an 1000 Hz siren. It is traveling at 35 m/s on a day when the speed
of sound through air is 350 m/s. The car approaches and passes an observer
who is standing along the roadside. What change of frequency does the
observer hear? Review Section 128 in Giancoli. 


17. 

You are
approaching a stationary sound of 1000 Hz at 35 m/s. What is the change in
frequency of the sound as you pass? Review Section 128 in Giancoli. 


18. 

The
wavelengths of the sounds produced by two horns are 6 m and 7 m respectively.
What beat frequency is heard when the horns are sounded on a day when the
velocity of sound is 336 m/s? Review Section 127 in Giancoli. 


19. 

The
wavelengths of the sounds produced by two horns are 6 m and 7 m respectively.
By how much would the temperature have to change for the beat frequency to be
9 Hz? That would be true if the initial was 0 C^{o}. Review Section 127 in Giancoli. 


20. 

For a
sound speed of 350 m/s, what would be the wavelength of a 5000 Hz sound? 


21. 

A sound
speed of 350 m/s (5000 Hz) is played. Another sound is played along with this
sound and a beat frequency of 5 Hz is heard. What is the frequency of the new
sound? 


22. 

What is
the frequency of the second harmonic of a 2 meter long stretched wire if the
wave speed is 171.5 m/s? This is the fourth harmonic. Review Section 125 in Giancoli. 


23. 

A 2 meter
long stretched wire has a wave speed of 171.5 m/s. What is the wavelength of
the sound produced by the vibrating wire if the temperature is 20 ^{o}C? You probably got the velocities backwards. Review Example 127 in Giancoli. 


24. 

What is
the frequency of the first overtone of an open organ pipe .52 m long at an
air temperature of 20 ^{o}C? 


25. 

What is
the frequency of the 2nd harmonic of a .52 m long closed organ pipe at a
temperature of 20 ^{o}C? The speed of sound is different than the wire speed. Review Example 127 in Giancoli. 