Zitsanzo za mafunso okhudza mphamvu ndi mphamvu ya mawu

Zitsanzo 11 za Mphamvu ya Phokoso ndi Magawo a Phokoso

1. Phokoso lili ndi mphamvu ya 1 x 10^-9 W / m²Kodi mulingo wa mphamvu mu ma decibel (dB) ndi wotani?
Zokambirana
Amadziwika kuti:
Ine = 1 x 10^-9 W / m²
I_o = 1x10 pa^-12 W / m²
Funso: Mlingo wa Mphamvu (dB)?
Yankho:

2. Mphamvu ya mawu m'chipinda ndi 100 dB. Kodi mphamvu ya mawu m'chipindamo ndi yotani?
Zokambirana
Amadziwika kuti:
TI = 100 dB
I_o = 1x10 pa^-12 W / m²
Funso: Kodi phokoso (I) lili bwanji m'chipindamo?
Yankho:

3. Mafunde awiri a phokoso ali ndi mphamvu ya 1 x 10^-5 W / m² ndi 1 x 10^-4 W / m²Kusiyana kwa mphamvu mu dB ndi…
Zokambirana
Amadziwika kuti:
I₁ = 10^-5 W / m²
I₂ = 10^-4 W / m²
I_o = 10^-12 W / m²
Funso: Kusiyana kwa mphamvu (TI) mu dB?
Yankho:
Kusiyana kwa mphamvu ya thupi?
TI₁ – IT₂ = 80 dB -70 dB = 10 dB

4. Dziwani chiŵerengero cha mphamvu ya mawu awiri omwe mphamvu yake ndi 10 dB ndi 40 dB.
Zokambirana
Amadziwika kuti:
TI₁ = 10db
TI₂ = 40db
I_o = 10^-12 W / m²
Kufunsidwa: Kuyerekeza mphamvu ya mawu awiriwa (I₁ : Ine₂)?
Yankho:

Kuyerekeza mphamvu ya magwero awiri a mawu:
I₁ : Ine₂
10^-11 : 10^-8

5. Mlingo wa mphamvu ya mawu wa malikhweru chikwi ofanana omwe amamveka pamodzi ndi 60 dB. Ngati malikhweru 10 ofanana amveka pamodzi, mlingo wa mphamvu umakhala….

1. 40 dB
2. 50 dB
3. 60 dB
4. 70 dB
5. 90 dB

Zokambirana

Amadziwika kuti:
Ma whistles a TI 1000 = 60 dB
Anafunsa kuti: Mphamvu ya level 10 whistles
Yankho:

Mlingo wa mphamvu ya 1 whistle:
TI 1000 whistles = TI whistle imodzi + 10 log x
60 = TI + 10 chipika 1000
60 = TI + 10 chipika 10³
60 = TI + (3)(10)(log 10)
60 = TI + (3)(10)(1)
60 = TI + 30
TI = 60 - 30
TI = 30 dB
Mphamvu ya mphuno imodzi ndi 30 dB.

Mlingo wa mphamvu ya 10 whistle:
TI 10 whistles = TI whistle imodzi + 10 log x
TI 10 whistles = 30 + 10 log 10
TI 10 whistles = 30 + 10 log 10¹
TI 10 whistles = 30 + (1)(10)(log 10)
TI 10 whistles = 30 + (1)(10)(1)
TI 10 whistles = 30 + 10
Ma whistles a TI 10 = 40 dB
Mphamvu ya ma whistles 10 ndi 40 dB.
Yankho lolondola ndi A.

6. Mphamvu ya mawu ya makina zana ofanana mu fakitale yopangira nsalu yomwe imagwira ntchito nthawi imodzi ndi 80 dB. Ngati mphamvu ya mawu ya makina ena ofanana ndi 90 dB, ndiye kuti chiwerengero cha makina omwe amagwiritsidwa ntchito panthawiyo ndi….

1. 1.000 buah
2. 500 buah
3. 100 buah
4. 50 buah
5. 10 buah

Zokambirana
Amadziwika kuti:
Makina a TI 100 = 80 dB
Anafunsa kuti: chiwerengero cha makina okhala ndi mphamvu ya 90 dB
Yankho:
Mphamvu ya makina 1:
Makina a TI 100 = Makina amodzi a TI + 10 log x
80 = TI + 10 chipika 100
80 = TI + 10 chipika 10²
80 = TI + (2)(10)(log 10)
80 = TI + (2)(10)(1)
80 = TI + 20
TI = 80 - 20
TI = 60 dB
Mphamvu ya makina amodzi ndi 60 dB.

Chiwerengero cha makina okhala ndi mphamvu ya 90 dB:
TI x makina = TI makina amodzi + 10 chipika x
90 = 60 + 10 chipika x
90 – 60 = 10 chipika x
30 = 10 chipika x
30 / 10 = chipika x
3 = pangano x
3 = pangano 1000

chipika 1000 = chipika 10 ³ = (3)(chipika 10) = (3)(1) = 3.

Chiwerengero cha makina omwe ali ndi mphamvu ya 90 dB ndi 1000.
Yankho lolondola ndi A.

7. Mphamvu ya mawu pamalo P, omwe ali pamtunda wa mamita 3 kuchokera ku gwero la mawu, ndi 10 ^-4 watt/m2 ^. Mfundo R ili pamtunda wa mamita 300 kuchokera ku gwero la mawu. Ngati mphamvu ya malire I ₀ = 10 ^-12 watt/m2 ^, ndiye kuti chiŵerengero cha mphamvu pa mfundo P ndi R ndi…

A. 1: 2
B. 2: 1
C. 2: 3
D. 2: 4
E. 3: 4

Zokambirana
Ndizodziwika kuti :
Mphamvu ya mawu pa mfundo P (I)_P= = 10^-4 W / m²
Mtunda wa mfundo P kuchokera ku gwero la mawu (r)_P) = mamita 3
Mtunda wa mfundo R kuchokera ku gwero la mawu (r_R) = mamita 300
Mphamvu ya malire (I)_o= = 10^-12 Watt/m²
Anafunsa Kuyerekeza kwa milingo yamphamvu pa mfundo P ndi R (TI)_P : IT_R)
Yankhani :

Fomula ya ubale pakati pa mphamvu ndi mtunda :
I_p r_p² = Ine_R r_R²
Mphamvu ya mawu pa R :
(10^-4)(3)²) = (Ine_R)(300)²)
(10^-4)(9) = (I_R) (90000)
9 × 10^-4 = (Ine_R)(9 x 10⁴)
I_R = 9x10 pa^-4 : 9 x 10^-4
I_R = 10^-8
Mphamvu ya phokoso pa mfundo R ndi 10^-8 W / m².
Mlingo wa mphamvu pa P :
Mlingo wa mphamvu mu R :
Kuyerekeza kwa TI pa mfundo P ndi R :
80 dB: 40 dB
2: 1
Yankho lolondola ndi B.

8. Mphamvu ya mawu pamalo A, omwe ali pamtunda wa mita imodzi kuchokera ku gwero la mawu, ndi 10 ^-7 W/m ^2. Mfundo B ili pamtunda wa mamita 100 kuchokera ku gwero la mawu. Ngati mphamvu ya malire ndi 10 ^-12 W/m ² , chiŵerengero cha mphamvu pa A ndi B ndi…

A. 5: 3
B. 5: 1
C. 4: 5
D. 4: 3
E. 3: 1

Zokambirana
Ndizodziwika kuti :
Mphamvu ya mawu pa mfundo A (I)_A= = 10^-7 W / m²
Mtunda wa mfundo A kuchokera ku gwero la mawu (r)_A) = mamita 1
Mtunda wa mfundo B kuchokera ku gwero la mawu (r)_R) = mamita 100
Mphamvu ya malire (I)_o= = 10^-12 Watt/m²
Anafunsa Kuyerekeza kwa milingo yamphamvu pa mfundo A ndi B_A : IT_B)
Yankhani :
Fomula ya ubale pakati pa mphamvu ndi mtunda :
I_A r_A² = Ine_B r_B²
Mphamvu ya mawu pa mfundo B :
(10^-7)(1)²) = (Ine_B)(100)²)
(10^-7)(1) = (I_B) (10.000)
1 × 10^-7 = (Ine_B)(1 x 10⁴)
I_B = 10^-7 : 10⁴
I_B = 10^-11
Mphamvu ya phokoso pa mfundo R ndi 10^-11 W / m².
Mlingo wa mphamvu pa mfundo A :
Mlingo wa mphamvu pa mfundo B :
Kuyerekeza kwa IT pa mfundo A ndi B :
50 dB: 10 dB
5: 1
Yankho lolondola ndi B.

9. Mapointi A ndi B ali ndi mtunda wa mamita 800 ndi mamita 400 motsatana kuchokera komwe mawu akuchokera. Ngati mu dera A mukumva phokoso la mphamvu ya mamita 10^-3 W / m², ndiye kufananiza kwa milingo yamphamvu ya mfundo A ndi B ndi… (log 2 = 0,3 ndi I_o = 10^-12 W / m²)
A. 11: 15
B. 15: 11
C. 15: 16
D. 16: 11
E. 16: 15
Zokambirana
Ndizodziwika kuti :
Mphamvu ya mawu pa mfundo A (I)_A= = 10^-3 W / m²
Mtunda wa mfundo A kuchokera ku gwero la mawu (r)_A) = mamita 800
Mtunda wa mfundo B kuchokera ku gwero la mawu (r)_B) = mamita 400
Mphamvu ya malire (I)_o= = 10^-12 Watt/m²
Logi 2 = 0,3
Anafunsa Kuyerekeza kwa milingo yamphamvu pa mfundo A ndi B (TI)_A : IT_B)
Yankhani :
Fomula ya ubale pakati pa mphamvu ndi mtunda :
I_A r_A² = Ine_B r_B²
Mphamvu ya mawu pa mfundo B :
(10^-3)(800)²) = (Ine_B)(400)²)
(10^-3)(640.000) = (I_B) (160.000)
(10^-3)(64) = (I_B) (16)
(10^-3)(4) = (I_B) (1)
I_B = 4x10 pa^-3 : 1
I_B = 4x10 pa^-3
Mphamvu ya phokoso pa mfundo B ndi 4 x 10^-3 W / m².
Mlingo wa mphamvu pa mfundo A :
Mlingo wa mphamvu pa mfundo B :
Chiŵerengero cha TI pa mfundo P ndi R ndi:
90 dB: 96 dB
15: 16
Yankho lolondola ndi C.

 10. Mapointi A ndi B ali pamtunda wa mamita atatu ndi mamita 8 kuchokera ku gwero la phokoso. Ngati ine_A ndipo ine_B Lililonse ndi mphamvu ya mawu pa mfundo A ndi mfundo B, kenako I_A : Ine_B ndi ...
A. 3: 2
B. 4: 9
C. 9: 4
D. 16: 81
E. 64: 9
Kukambirana:
Ndizodziwika kuti :
r_A = 3 m, r_B = 8 m
Anafunsa :
I_A : Ine_B ?
Yankhani :
Mphamvu ya mawu imasiyana kwambiri ndi sikweya ya mtunda wa mfundo kuchokera ku gwero la mawu:
Yankho lolondola ndi E.

11. Mtunda wochokera ku A kupita ku gwero la mawu ndi mtunda wowirikiza katatu/kachinayi kuposa mtunda wochokera ku B kupita ku gwero la mawu. Ngati mphamvu ya mawu omwe A amamva ndi I_o, ndiye mphamvu yomwe B adamva ndi...
A. 1/3 Io
B. 2/3 Io
C. 3/4 Io
D. 9/4 Io
E. 9/16 Io
Kukambirana:
Ndizodziwika kuti :
r_A = 3/4r, r_B = r, Ine_A = Ine_o
Anafunsa :
I_B =?
Yankhani :

Yankho lolondola ndi E.

Mafunso okhudza mphamvu ndi kuchuluka kwa mphamvu ya mawu

1. Mpira umaponyedwa molunjika pansi kuchokera ku nyumba yokhala ndi zipinda zambiri yokhala ndi liwiro loyamba la 4 m/s ndipo umafika pansi patatha masekondi atatu. Kodi liwiro la mpirawo ndi lotani ukagunda pansi?
Yankho:
v_t = 30 m/s
2. Mwala umaponyedwa m'chitsime ndi liwiro loyamba la 12 m/s ndipo umagunda pamwamba pa chitsimecho madzi atatha masekondi atatu. Kodi chitsimecho chili chozama bwanji?
Yankho:
h = mamita 55
3. Kuchokera pa nyumba yotalika mamita 100, phukusi limaponyedwa molunjika pansi pa liwiro la 5 m/s. Dziwani (a) nthawi yomwe phukusi lifike pansi (b) Liwiro la phukusi likafika pansi
Yankho:
(a) t = masekondi 4 (b) v_t = 45 m/s