Nā nīnau hoʻohālike no ka nalo kani

16 mau laʻana o nā nīnau no ka nalo leo

1. Lohe ka mea nānā ma kahi heihei kaʻa i nā leo like ʻole (ka uwo ʻana o nā kaʻa) i ka wā e hoʻokokoke mai ai a hoʻi hope ai nā kaʻa. Hoʻopuka ke kaʻa heihei maʻamau i kahi leo ma 800 Hz. Inā he 340 m/s ka wikiwiki o ke kani i ka lewa,^-1 a ʻo ka wikiwiki o ke kaʻa he 20 ms^-1, a laila ʻo ke alapine (frequency) i lohe ʻia i ka wā e hoʻokokoke mai ai ke kaʻa he….
A. 805 Hz

B. 810 Hz

C. 815 Hz

D. 850 Hz

E. 875 Hz

Pahana

Ua ʻike ʻia:

v _s = -20 m/s (maikaʻi ʻole no ka mea e neʻe ana ke kaʻa mai ka mea hoʻolohe)

v _p = 0 (ua noho mālie ka mea hoʻolohe no ka mea ke nānā nei ʻo ia)

f = 800 hz

v = 340 m/s

Nīnau ʻia: He aha ke alapine (frequency) o ke kani āu e lohe nei?

Pane:

ʻO D ka pane pololei.

2. Neʻe kekahi kanaka ma ka wikiwiki o 10 m/s ⁻¹ i kahi kumu leo ​​paʻa me ka alapine (frequency) o 680 Hz. Ma hope o ka hiki ʻana i ke kumu leo, neʻe aku ke kanaka mai ke kumu leo ​​aku ma ka wikiwiki like. Inā he 340 m/s ⁻¹ ka wikiwiki o ke kumu leo ​​i ka lewa , a laila ʻo ka lakio o nā alapine ʻelua i lohe ʻia i ka neʻe ʻana i ke kumu i ka neʻe ʻana aku mai ke kumu he...

A. 33/34

B. 33/35

C. 34/35

D. 35/33

E. 35/34

Pahana

Ua ʻike ʻia:

v = 340 m/s

v _p = 10 m/s

vs ₌ 0

f = 680 hz

Nīnau: He aha ka lakio o ke alapine kani ke hoʻokokoke aku ka mea hoʻolohe i ke kumu me ka neʻe ʻana o ka mea hoʻolohe mai ke kumu?

Pane:

Neʻe aku ka mea hoʻolohe mai ke kumu mai:

Hoʻohālikelike ʻana o nā alapine (frequency) i lohe ʻia:

700 : 660 = 70 : 66 = 35 : 33

ʻO D ka pane pololei.

3. Ke hoʻokokoke aku nei kahi lokomotive kaʻaahi e holo ana ma ka wikiwiki o 72 km/h i kahi keʻena kaʻaahi me ke kani ʻana i ka whiowhio me ka alapine (frequency) o 1600 Hz. Inā he 340 ms-1 ka wikiwiki o ke kani i ka lewa, a laila ʻo ke alapine (frequency) o ka whiowhio i lohe ʻia e ke kiaʻi keʻena kaʻaahi he ….

A. 3600 Hz

B. 3400 Hz

C. 1800 Hz

D. 1700Hz

E. 1400Hz

Pahana

Ua ʻike ʻia:

Ka wikiwiki o ke kumu kani (vs ₎ = 72 km/h = 20 m/s (e pili ana i ka mea hoʻokele leo)

Alapine (frequency) o ke kumu leo ​​(f) = 1600 Hz

Ka wikiwiki o ke kani i ka lewa (v) = 340 m/s

Ka wikiwiki o ka mea hoʻolohe (v _p ) = 0 (ʻole no ka mea ʻaʻole e neʻe ana ka mea hoʻolohe)

Nīnau ʻia: alapine (frequency) o ke kani i lohe ʻia e ke kiaʻi (f')?

Pane:

ʻO D ka pane pololei.

4. Ke neʻe nei kekahi kaʻa kinai ahi ma ka wikiwiki o 20 ms ^-1 ʻoiai e kani ana i kāna siren ma ke alapine (frequency) o 400 Hz (ʻo ka wikiwiki o ke kani i ka lewa he 300 ms ^-1 ). Inā neʻe aku ke kaʻa kinai ahi mai kahi kanaka e kū ana ma ka ʻaoʻao o ke alanui, e lohe ke kanaka i ka siren ma ke alapine o….

A. 375 Hz

B. 575 Hz

C. 600 Hz

D. 620 Hz

E. 725 Hz

Pahana

Ua ʻike ʻia:

v _s = 20 m/s (maikaʻi no ka mea e neʻe ana ke kaʻa mai ka mea hoʻolohe)

v _p = 0 (mea hoʻolohe leo ʻole ma ka ʻaoʻao o ke alanui)

f = 400 hz

v = 300 m/s

Nīnau ʻia: He aha ke alapine (frequency) o ke kani āu e lohe nei?

Pane:

ʻO A ka pane pololei.

5. Hoʻopuka kahi mea hoʻolele leo mai kahi hale kiaʻi hoʻolaha i kahi leo ma ke alapine (frequency) o 670 Hz. Hoʻokokoke aku kahi kaʻa i ka hale kiaʻi ma ka wikiwiki o 90 km/h. Inā ʻo ka wikiwiki o ke kani i ka lewa i kēlā manawa he 335 m/s, a laila ʻo ke alapine (frequency) o ke kani mai ka mea hoʻolele leo i lohe ʻia e ka mea hoʻokele kaʻa he…

A. 900 Hz

B. 840 Hz

C. 800 Hz

D. 750 Hz

E. 720 Hz

Pahana

Ua ʻike ʻia:

f = 670 hz

v _s = 0 (hale kiaʻi i ka wā hoʻomaha)

v _p = 90 km/h = 25 m/s (maikaʻi no ka mea ke hoʻokokoke aku nei ka mea hoʻolohe i ke kumu kani)

v = 335 m/s

Nīnau: He aha ke alapine (frequency) o ke kani i lohe ʻia e ka mea hoʻokele (f')?

Pane:

ʻO ka pane pololei ʻo E.

6. Aia ʻo Dini ma luna o ke kaʻaahi A i kū. Ke neʻe nei kekahi kaʻaahi (B) i A ma ka wikiwiki o 2 ms^-1 ʻoiai e puhi ana i ka ʻūlili me ke alapine (frequency) o 676 Hz. Inā he 340 ms ka wikiwiki o ke kani i ka lewa^-1, a laila ʻo ke alapine (frequency) o ke kani ʻana o ke kaʻaahi B a Dini i lohe ai ʻo ia….
A. 680 Hz

B. 676 Hz

C. 660 Hz

D. 656 Hz

E. 640 Hz

Pahana

Ua ʻike ʻia:

v _s = -2 m/s (hoʻokokoke ke kaʻaahi maikaʻi ʻole B iā Dini a me ke kaʻaahi A

v _p = 0 (Aia ʻo Dini ma luna o ke kaʻaahi i kū)

f = 676 hz

v = 340 m/s

Nīnau ʻia: He aha ke alapine (pinepine) o ke kaʻaahi B a Dini i lohe ai?

Pane:

ʻO A ka pane pololei.

7. Holo kahi mea pāʻani pôpeku ma ka wikiwiki o v _p i kahi luna kānāwai kū ʻoiai e puhi ana i ka ʻūlū me ka alapine (frequency) o f _s . Inā ʻo v ka wikiwiki o ka ea ma ia wahi, a laila ua hoʻohālikelike ʻia ke alapine (frequency) i lohe ʻia e ka mea pāʻani penei….

Pahana

Ua ʻike ʻia :

v _s = 0 (ua noho mālie ka luna kānāwai)

v _p = v _p (maikaʻi no ka mea ke hoʻokokoke aku nei i ke kumu kani)

f = _fs

v = v

Nīnau : He aha ke ʻano alapine (frequency) i lohe ʻia e nā mea pāʻani pôpeku?

Pane :

ʻO A ka pane pololei.

8. Ke neʻe nei ka Ambulance A ma ka wikiwiki o 0,25 v ma hope o ke kaʻa sedan B e neʻe ana ma ka wikiwiki o 0,2 v ma ke kuhikuhi like me A. I kēlā manawa, kani ka ambulance A i kāna siren ma 1.000 Hz. Inā ʻo v ka wikiwiki o ke kani, ʻo ke alapine (frequency) i lohe ʻia e ka mea hoʻokele o ke kaʻa sedan B…

A. 1.500 Hz

B. 1.250 Hz

C. 1.111 Hz

D. 1.067 Hz

E. 1.000 Hz

Pahana

Ua ʻike ʻia :

Alapine (frequency) o ke kumu leo ​​(f) = 1.000 Hz

Ka wikiwiki o ke kumu kani (vs ₎ = -0,25 v (e pili ana i ka mea e lawe ana i ke kani)

Ka wikiwiki o ke kani (v) = v

Ka wikiwiki o ka mea hoʻolohe (vp ₎ = -0,2 v (e pili ana i ka mea e lawe ana i ke kani)

Makemake ʻia : Alapine (frequency) o ke kani i lohe ʻia e ka mea hoʻolohe (f')

Pane :

ʻO ke ʻano hana Doppler:

ʻO D ka pane pololei.

9. Neʻe aku kahi kumu leo ​​me ke alapine (frequency) o 640 Hz i kahi mea nānā ma ka wikiwiki o 20 m/s. Inā he 340 m/s ka wikiwiki o ke kani i ka lewa a neʻe aku ka mea nānā mai ke kumu leo ​​ma ka wikiwiki o 10 m/s, a laila ʻo ke alapine (frequency) o ke kani i lohe ʻia e ka mea nānā…

A. 600 Hz

B. 660 Hz

C. 900 Hz

D. 980 Hz

E. 1300 Hz

Pahana

Ua ʻike ʻia :

Alapine (frequency) o ke kumu leo ​​(f) = 640 Hz

Ka wikiwiki o ke kumu kani (vs ₎ = -20 m/s (e pili ana i ka ea ma ke ʻano he mea hoʻokele leo)

Ka wikiwiki o ke kani (v) = 340 m/s (e pili ana i ka ea ma ke ʻano he mea hoʻoili leo)

Ka wikiwiki o ka mea hoʻolohe (v _p ) = -10 m/s (e pili ana i ka ea ma ke ʻano he mea hoʻokele leo)

Makemake ʻia : Alapine (frequency) o ke kani i lohe ʻia e ka mea hoʻolohe (f')

Pane :

ʻO ka pane pololei ʻo B.

10. Neʻe kahi kumu leo ​​i ka wikiwiki o 60 m/s e waiho ana i kahi mea nānā ma hope ona e neʻe ana ma ke kuhikuhi like me ke kumu leo ​​i ka wikiwiki o 10 m/s. Inā ʻo ka wikiwiki o ke kani i ka lewa he 340 m/s a ʻo ke alapine o ke kumu leo ​​he 800 Hz, a laila ʻo ke alapine o ke kani i lohe ʻia e ka mea nānā…

A. 700 Hz

B. 800 Hz

C. 940 Hz

D. 960 Hz

E. 1.120 Hz

Pahana

Ua ʻike ʻia :

Alapine (frequency) o ke kumu leo ​​(f) = 800 Hz

Ka wikiwiki o ke kumu kani (vs ₎ = 60 m/s (e pili ana i ka ea ma ke ʻano he mea hoʻokele leo)

Ka wikiwiki o ke kani (v) = 340 m/s (e pili ana i ka ea ma ke ʻano he mea hoʻoili leo)

Ka wikiwiki o ka mea hoʻolohe (v _p ) = 10 m/s (e pili ana i ka ea ma ke ʻano he mea hoʻokele leo)

Makemake ʻia : Alapine (frequency) o ke kani i lohe ʻia e ka mea hoʻolohe (f')

Pane :

ʻO A ka pane pololei.

Ka ikaika o ke kani

11. ʻO ka ikaika o ke kani ma ke kiko P, ʻo ia hoʻi he 3 m mai ke kumu kani, he 10 ^-4 watt/m² ^. ʻO ke kiko R he 300 m mai ke kumu kani. Inā ʻo ka ikaika paepae I ₀ = 10 ^-12 watt/m² ^, a laila ʻo ka lakio o nā pae ikaika ma nā kiko P a me R he…

A. 1 : 2

B. 2 : 1

K. 2 : 3

D. 2 : 4

E. 3 : 4

Pahana

Ua ʻike ʻia :

Ka ikaika o ke kani ma ke kiko P (IP ₎ = 10 ^-4 W/ ^m2

Ka mamao o ke kiko P mai ke kumu kani (r _P ) = 3 mika

Ka mamao o ke kiko R mai ke kumu kani (r _R ) = 300 mika

Ka ikaika paepae (I _o ) = 10 ^-12 Watt/ ^m2

Nīnau : Hoʻohālikelike i nā pae ikaika ma nā kiko P a me R (TI _P : TI _R )

Pane :

ʻO ke ʻano hana no ka pilina ma waena o ka ikaika a me ka mamao :

I _p r _p ² = I _R r _R ²

Ka ikaika o ke kani ma R :

(10 ^-4 )(3 ² ) = (I _R )(300 ² )

(10 ^-4 )(9) = (I _R )(90000)

9 x 10 ^-4 = (I _R )(9 x 10 ⁴ )

IR ₌ 9 x 10 ^-4 : 9 x 10 ^-4

IR ₌ 10 ^-8

ʻO ka ikaika o ke kani ma ke kiko R he 10 ^-8 W/ ^m2.

Hoʻohālikelike ʻana o TI ma nā kiko P a me R :

80 dB : 40 dB

2: 1

ʻO ka pane pololei ʻo B.

12. ʻO ka ikaika o ke kani ma ke kiko A, ʻo ia hoʻi he 1 mika mai ke kumu kani, he 10 ^-7 W/m2 ^. ʻO ke kiko B he 100 mika mai ke kumu kani. Inā ʻo ka ikaika paepae he 10 ^-12 W/m2 ^, ʻo ka lakio o nā pae ikaika ma A a me B he…

A. 5 : 3

B. 5 : 1

K. 4 : 5

D. 4 : 3

E. 3 : 1

Pahana

Ua ʻike ʻia :

Ka ikaika o ke kani ma ke kiko A (IA ₎ = 10 ^-7 W/ ^m2

Ka mamao o ke kiko A mai ke kumu kani (r _A ) = 1 mika

Ka mamao o ke kiko B mai ke kumu kani (r _R ) = 100 mika

Ka ikaika paepae (I _o ) = 10 ^-12 Watt/ ^m2

Nīnau : Hoʻohālikelike ʻana o nā pae ikaika ma nā wahi A a me B (TI _A : TI _B )

Pane :

ʻO ke ʻano hana no ka pilina ma waena o ka ikaika a me ka mamao :

I _A r _A ² = I _B r _B ²

Ka ikaika o ke kani ma ke kiko B :

(10 ^-7 )(1 ² ) = (I _B )(100 ² )

(10 ^-7 )(1) = (I _B )(10.000)

1 x 10 ^-7 = (I _B )(1 x 10 ⁴ )

IB = 10 ^-7 _: 10 ⁴

ʻO _IB = 10 ^-11

ʻO ka ikaika o ke kani ma ke kiko R he 10 ^-11 W/ ^m2.

Hoʻohālikelike ʻana o IT ma nā wahi A a me B :

50 dB : 10 dB

5: 1

ʻO ka pane pololei ʻo B.

13. He 800 m a me 400 m ka mamao o nā kiko A a me B mai ke kumu kani. Inā ma kahi A ʻoe e lohe ai i kahi kani me ka ikaika o 10 ^-3 W/m² ^, a laila ʻo ka lakio o nā pae ikaika ma nā kiko A a me B ʻo ia... (log 2 = 0,3 a me Io ₌ 10 ^-12 W/ ^m² )

A. 11 : 15

B. 15 : 11

K. 15 : 16

D. 16 : 11

E. 16 : 15

Pahana

Ua ʻike ʻia :

Ka ikaika o ke kani ma ke kiko A (IA ₎ = 10 ^-3 W/ ^m2

Ka mamao o ke kiko A mai ke kumu kani (r _A ) = 800 mika

Ka mamao o ke kiko B mai ke kumu kani (r _B ) = 400 mika

Ka ikaika paepae (I _o ) = 10 ^-12 Watt/ ^m2

Log 2 = 0,3

Nīnau : Hoʻohālikelike ʻana o nā pae ikaika ma nā wahi A a me B (TI _A : TI _B )

Pane :

ʻO ke ʻano hana no ka pilina ma waena o ka ikaika a me ka mamao :

I _A r _A ² = I _B r _B ²

Ka ikaika o ke kani ma ke kiko B :

(10 ^-3 )(800 ² ) = (I _B )(400 ² )

(10 ^-3 )(640.000) = (I _B )(160.000)

(10 ^-3 )(64) = (I _B )(16)

(10 ^-3 )(4) = (I _B )(1)

IB ₌ 4 x 10 ^-3 : 1

ʻO _IB = 4 x 10 ^-3

ʻO ka ikaika o ke kani ma ke kiko B he 4 x 10 ^-3 W/ ^m2.

ʻO ka lakio TI ma nā kiko P a me R:

90 dB : 96 dB

15: 16

ʻO C ka pane pololei.

Nā pae ikaika a me ke kani

14. Papa o nā pae ikaika no kēlā me kēia kumu kani.

Puna kani	Pae Ikaika o ke Kani (TI)
Ke kani ʻana o nā manu	80 dB
Siren kaʻa kaʻa	100 dB
Hekili (uila)	160 dB

Hoʻopuka kahi ʻenekini kaʻa i kahi pae ikaika leo o TI = 70 dB (I _o = 10 ⁻¹² Watt m ⁻² ). I mea e hoʻopuka ai ke kani ʻenekini i kahi pae ikaika e like me ke kani o kahi siren ambulance, ʻo ka helu o nā ʻenekini kaʻa e pono ai….

A. 20.00 mīkini
Mīkini B. 30.00
Nā mīkini C. 100.0
D. 1.000 mau mīkini
E. 3.000 mau mīkini

Pahana
Ua ʻike ʻia :
Kaʻa TI = 70 dB
Kaʻa kaʻa kaʻa TI = 100 dB
I_o = 10^-12 Watt/m²
Ua nīnau ʻia Ehia mau ʻenekini kaʻa e like ai ka IT o ke kaʻa me ka IT o ka ambulance?
Pane :

Ambulance TI = kaʻa TI + 10 log x
100 = 70 + 10 log x
100 – 70 = 10 log x
30 = 10 log x
30 / 10 = log x
3 = log x
Antilog 3 = x
10³ =x
1000 = x
ʻO D ka pane pololei.

15. He 60 dB ka pae ikaika o kahi kumu kani (I _o = 10 ^{– 12} watts m ^–2 ). Ke kani like nā kumu kani like he 100 i ka manawa like, ʻo ka pae ikaika o ke kani i loaʻa mai...

A. 62 dB
B. 80 dB
C. 82 dB
D. 100 dB
E. 160 dB

Pahana
Ua ʻike ʻia :
TI = 60 dB
I_o = 10^-12 W / m²
x = 100
Ua nīnau ʻia : Kumu kani TI 100?
Pane :
Nā kumu leo ​​TI 100 = mīkini TI 1 + 10 log x
TI = 60 + 10 log 100
TI = 60 + 10 log 10²
TI = 60 + (2)(10)(log 10)
TI = 60 + 20
TI = 80 dB
ʻO ka pane pololei ʻo B.

Ka hopena Doppler
16. Holo ka mea pāʻani pôpeku me ka wikiwiki v_p i ka luna kānāwai i noho mālie ʻoiai e puhi ana i ka ʻūlili ma ke alapine (frequency) o f_s. Inā ʻo v ka wikiwiki o ka ea ma ia wahi, a laila ua hoʻohālikelike ʻia ke alapine (frequency) i lohe ʻia e ka mea hoʻokani pila penei….

Pahana
Ua ʻike ʻia :
v_s = 0 (ua noho mālie ka luna kānāwai)
v_p = v_p (maikaʻi no ka mea kokoke ia i ke kumu kani)
f = f_s
v = v
Ua nīnau ʻia : he aha ke ʻano alapine (frequency) i lohe ʻia e nā mea pāʻani pôpeku?
Pane :

ʻO A ka pane pololei.

Puna nīnau:

Nā Nīnau Hoʻokolohua Lahui no ke Kino no ke Kula Kiʻekiʻe/Kula Kiʻekiʻe ʻOihana