際際滷

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Yiying	
 Lin	
 15621148	
 
LO	
 7/8	
 
	
 
Short	
 answer	
 question:	
 
	
 
The	
 sound	
 produced	
 by	
 an	
 object	
 has	
 a	
 wavelength	
 1m	
 in	
 the	
 air;	
 the	
 wave	
 speed	
 
is	
 340	
 meters	
 per	
 second.	
 It	
 has	
 a	
 wavelength	
 4.5m	
 in	
 the	
 sea.	
 This	
 object	
 emits	
 a	
 
sound	
 at	
 the	
 surface	
 of	
 the	
 sea,	
 and	
 the	
 echo	
 can	
 be	
 received	
 after	
 0.5	
 second.	
 
Therefore,	
 how	
 deep	
 is	
 the	
 sea	
 is?	
 
	
 
	
 
	
 
	
 
	
 
	
 
	
 
	
 
	
 
	
 
Answer:	
 use	
 both	
 v=了f	
 and	
 wave	
 propagation	
 to	
 solve	
 this	
 question.	
 
In	
 different	
 mediums,	
 same	
 sound	
 waves	
 will	
 have	
 same	
 frequency.	
 
Frequency=	
 vair/了air	
 
In	
 the	
 sea:	
 vsea=vair(了sea/了air)=1530m/s	
 
h	
 =	
 vsea(t/2)=1530x0.5x0.2	
 =	
 382.5m

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Lo 7(2)

  • 1. Yiying Lin 15621148 LO 7/8 Short answer question: The sound produced by an object has a wavelength 1m in the air; the wave speed is 340 meters per second. It has a wavelength 4.5m in the sea. This object emits a sound at the surface of the sea, and the echo can be received after 0.5 second. Therefore, how deep is the sea is? Answer: use both v=了f and wave propagation to solve this question. In different mediums, same sound waves will have same frequency. Frequency= vair/了air In the sea: vsea=vair(了sea/了air)=1530m/s h = vsea(t/2)=1530x0.5x0.2 = 382.5m