TUTORIAL ANSWERS 160-170


 
 
 

Your answer to Q160:  Sorry, your answer is not correct.  What does the question mean by "flat"?

Help: Fundamentals of Sound, Sec. 2-A.

Or, would you like a HINT?

You should really try to work out the answer on your own, but if you insist on reading it, the correct answer is HERE.

Return to Question 160.
 


 

Hint for Q160:  A flat wave occurs when there are no peaks or troughs at all in the string—it is absolutely level throughout.

    Return to Question 160.


 

Your answer to Q160:  Congratulations, your answer is correct!

    To read the "official" correct answer, click HERE.

    Return to Question 160.
 


 

Correct answer to Q160:  The string is flat every half cycle—when a peak passes down to become a trough, and when it passes up to become a peak again. The time for that is 1/2 period. b) is correct.

    Return to Question 160.
 
 
 
 
 


 
 
 

Your answer to Q165:  Sorry, your answer is not correct. 

Help: Fundamentals of Sound, Table 3-1.

Would you like a HINT?

You should really try to work it out on your own, but if you insist on reading it, the correct answer is HERE.

    Return to Question 165.
 
 


 

Hint for Q165:  Table 3-1 gives the relation between any frequency or wavelength and that of the fundamental.

    Return to Question 165.
 


 

Your answer to Q165:  Congratulations, your answer is correct!

    To read the "official" correct answer, click HERE.

    Return to Question 165.
 


 

Correct answer to Q165:  True is the correct answer. Table 3-1 at the end of Chapter 3 gives a listing of the frequencies and wavelengths of waves with all the boundary conditions that we have considered. For example, the frequency of a wave tied at both ends is nf0, where n=1,2,3... Note however that if the wave has one open end and one closed end that the even harmonics are skipped and n=1,3,5...

    Return to Question 165.
 
 


 
 

Your answer to Q170:  Sorry, your answer is not correct. Note that the tube has one end open and the other end closed.

Help: Fundamentals of Sound, Sec. 3-D.

Or, would you like a HINT?

You should really try to work out the answer on your own, but if you insist on reading it, the correct answer is HERE.

Return to Question 170.
 


 

Hint for Q170:  Look at the distribution of air molecules. There is a compression at the left end and just normal pressure at the right end.

    Return to Question 170.
 


 

Your answer to Q170:  Congratulations, your answer is correct!

    To read the "official" correct answer, click HERE.

    Return to Question 170.
 


 

Correct answer to Q170:  There is a compression at the left end and normal pressure at the right end. No other pressure nodes or antinodes occur. The pressure graph in d) shows the proper form. The displacement must be uniformly towards to left end to form the compression; that is negative displacement as shown in d) as well. The displacement is maximum to the right at the open end.

    Return to Question 170.
 
 


 
 
 
 

 

 


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