1© Manhattan Press (H.K.) Ltd. 10.6 Resonance tube – Measurement of speed of sound in air.

© Manhattan Press (H.K.) Ltd. 1

10.6 Resonance tube – 10.6 Resonance tube – Measurement of speed Measurement of speed

of sound in airof sound in air


10.6 Resonance tube – Measurement of speed of sound in air (SB p. 148)

Resonance tube

Vibrate tuning fork over open end of tube- air column in tube is vibrated

fv

fvc

fvc

2

43

43

44

21

2

1

Speed of sound in air v = 2f (2 – 1)



Resonance tube

c,f

vv

cvf

fvc

1

1

1

01When

graph ofGradient 4air in sound of Speed

4Gradient

41

4

Go to

Example 8Example 8

Go to

Example 9Example 9


End



Q:Q: A tuning fork of frequency 250 Hz is used with

a resonance tube, closed at one end, to measure the speed of sound in air. The resonant lengths are found to be 0.30 m and 0.96 m. Calculate(a) the speed of sound, and(b) the end correction of the tube.

Solution



Solution:Solution:

Return to

TextText

m 030300

4321300

4 correction end

1equation Using(b)s m 330321250 sound of Speed

m 321 210.66 12

2430.96

m, 0.96 islength resonant the When

14

0.30

m, 0.30 oflength resonant first For the (a)

1

....c

,.fv

.

................c

..................c



Q:Q:

A vibrating tuning fork is held near the end A of a tube AB. The piston P is moved slowly from A to B. A loud sound is first heard when AP is 0.15 m, and the next when AP is 0.47 m (see figure above). (a) For the second resonant length, draw a graph showing how the amplitude a of vibration of the air particles in the tube varies with the distance x from P.(b) Explain why the relationship between the two resonant lengths is not a simple ratio.

Solution



Solution:Solution:

(a)



Solution (cont’d) :Solution (cont’d) :

m 0.01 150

4640 1 from and

m 0.64,211500.47 12

ratio. simplenot iswhich

41

43

0.150.47

12

243 ,0.47

430.47 length,resonant second For the

14

0.15 ,4

0.15 length,resonant first For the

.correction end thebe Let tube. theof endopen thebeyond extend particlesair theof s vibration thebecause ratio simple anot is lengthsresonant two theof ratio The (b)

..c

.

c

c

........cc

..............cc

c

Return to

TextText

1© Manhattan Press (H.K.) Ltd. 10.6 Resonance tube – Measurement of speed of sound in air.

Documents

Transcript of 1© Manhattan Press (H.K.) Ltd. 10.6 Resonance tube – Measurement of speed of sound in air.