Lecture Sonic Boom.notebook February 08, 2013

Transcription

1 A plane flying at sub sonic speed (below the speed of sound), emits sound waves that can be represented like this: Doppler Effect:

2 What would the sound waves look like as the plane approached the speed of sound?

3 What would the sound waves look like as the plane approached the speed of sound? The plane flies just as fast as the sound waves it emits:

4 What would the sound waves look like as the plane approached the speed of sound? The plane flies just as fast as the sound waves it emits:

5 What would the sound waves look like as the plane approached the speed of sound? The plane flies just as fast as the sound waves it emits:

6 What would the sound waves look like as the plane approached the speed of sound? The plane flies just as fast as the sound waves it emits:

7 What would the sound waves look like as the plane approached the speed of sound? The plane flies just as fast as the sound waves it emits:

8 What would the sound waves look like as the plane approached the speed of sound? The plane flies just as fast as the sound waves it emits: Big Pressure wave gets built up. We have a combination of Constructive Interference and Doppler

9 What happens if the plane flies faster than the speed of sound?

10 What happens if the plane flies faster than the speed of sound?

11 What happens if the plane flies faster than the speed of sound?

12 What happens if the plane flies faster than the speed of sound?

13 What happens if the plane flies faster than the speed of sound?

14 What happens if the plane flies faster than the speed of sound?

15 What happens if the plane flies faster than the speed of sound?

16 What happens if the plane flies faster than the speed of sound?

17 What happens if the plane flies faster than the speed of sound?

18 What happens if the plane flies faster than the speed of sound?

19 What happens if the plane flies faster than the speed of sound? This is called a BOW WAVE:

20 What happens if the plane flies faster than the speed of sound? What does Ryu hear here?

21 What happens if the plane flies faster than the speed of sound? What does Ryu hear here? NOTHING!!!

22 What happens if the plane flies faster than the speed of sound? What does Ryu hear here?

23 SONIC BOOM!!!

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26 Along the edges of the wave front we get a build up of sound waves (air pressure waves).

27 Along the edges of the wave front we get a build up of sound waves (air pressure waves). When the 'wake' of the wave front (from constructive interference) reaches the listener below, they hear a sonic boom!!!

28 Lecture Sonic Boom.notebook February 08, 2013 F-14 breaks sound barrier F-14 break and roll Buzz the tower F-18 Sonic Boom

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30 As the sound waves from the jet are compressed, the water vapor in the air is condensed, creating a vapor cloud around the jet as it reaches and then passes the sound barrier.

31 Scroll down or full screen me!!!

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34 But how can I tell how fast the plane is flying?

35 r If the jet is stationary, sound waves spread out spherically at the speed of sound (340 m / s ).

36 MACH 1 r r If the jet is stationary, sound waves spread out spherically at the speed of sound (340 m / s ). If the jet travels at the speed of sound, the distance the plane travels every second is equal to the radius of the sound wave.

37 MACH 1 Again, we just get this pattern of sound waves.

38 Simulation Time!!! index.html

39 Doppler Effect & Sound for Super Sonic Speeds: CLICK ME!!! 12/airplane/sndwave.html

40 What happens if the plane travels twice the speed of sound? (MACH 2 = 680 m / s )

41 What happens if the plane travels twice the speed of sound? (MACH 2 = 680 m / s ) MACH 2 r r As the sound wave moves, the jet moves double the radius of the sound wave.

42 What happens if the plane travels four times the speed of sound? (MACH 4 = 1,360 m / s )

43 What happens if the plane travels four times the speed of sound? (MACH 4 = 1,360 m / s ) MACH 4 r r r r As the sound wave moves, the jet moves four times the radius of the sound wave.

44 What happens if the plane travels four times the speed of sound? (MACH 4 = 1,360 m / s ) MACH 4 The sound cone gets longer and narrower: r r r r As the sound wave moves, the jet moves four times the radius of the sound wave.

45 His physics lesson learned, Ryu now travels to combat his next challenge, completing WB 25 1 & Let's join him!!!

46 Attachments F 14.mpeg F 14 Boom and Roll.avi F 18 boom and F 14 fly by.wmv ShockWave.mpeg index.html ryu stage.mp3