speed of sound question, please help :)

Question

A musical instrument has an open/closed air tube which is 32 cm long. If the speed of sound in air is 350 m/s then find the fundamental frequency for this instrument. Give your answer ...
in terms of Hertz. 
to a precision of integer Hertz. Use a format like ### in your answer.
to an accuracy of 2 Hz.

 

thank you :)

Answer 1

Case 1

Open pipe ( open at both ends)

For fundamental Length of pipe = 2x Wave length /4= wave length /2

 

So wave length = 2x Length of pipe = 2*32 = 64 cm = 0.64 m

Speed = Frequency* wave length 

 Frequency= 350/0.64 

= 546.875 Hz or 546 (+/- ) 2 Hz

 

Case 2 ( closed pipe ) which is closed at one end and open at other

 

Length of Pipe = Wave length / 4

Wave length = 4 *0.32 = 1.28 m

 frequency = 350/1.28 = 273.43 Hz  or 273 (+/- ) 2 Hz