Lipotso tsa Mohlala oa Maqhubu a Molumo

Mehlala e 16 ea lipotso tsa Maqhubu a Molumo

1. Moshebelli peisong ea likoloi o utloa melumo e fapaneng (molumo oa likoloi) ha likoloi li ntse li atamela 'me li khutlela morao. Koloi e tloaelehileng ea peiso e hlahisa molumo oa 800 Hz. Haeba lebelo la molumo moeeng e le 340 m/s,^-1 'me lebelo la koloi ke 20 ms^-1, ebe maqhubu a utlwahalang ha koloi e atamela ke….
A. 805 Hz

B. 810 Hz

C. 815 Hz

D. 850 Hz

E. 875 Hz

Puisano

Hoa tsebahala hore:

v_s = -20 m/s (e mpe hobane koloi e suthela hole le momameli)

v_p = 0 (momameli o khutsitse hobane o shebelletse)

f = 800 hz

v = 340 m/s

Botsitswe: O utlwa modumo o kae?

Karabo:

Karabo e nepahetseng ke D.

2. Motho o tsamaea ka lebelo la 10 ms^-1 Ha e atamela mohlodi wa modumo o sa sisinyeheng, maqhubu a mohlodi wa modumo ke 680 Hz. Kamora ho fihla mohloding wa modumo, motho o tloha mohloding wa modumo ka lebelo le tshwanang. Haeba lebelo la mohlodi wa modumo moyeng e le 340 m/s^-1, ebe papiso ea maqhubu a mabeli a utluoang ha ho leba mohloling le ha ho leba hole le mohloli ke...

A. 33/34

B. 33/35

C. 34/35

D. 35/33

E. 35/34

Puisano

Hoa tsebahala hore:

v = 340 m/s

v_p = 10 m/s

v_s = 0

f = 680 hz

Potso: Karolelano ea maqhubu a molumo ke efe ha momameli a atamela mohloli ha momameli a suthela hole le mohloli?

Karabo:

Momameli o tloha mohloling:

Papiso ea maqhubu a utluoang:

700: 660 = 70: 66 = 35: 33

Karabo e nepahetseng ke D.

3. Terene e tsamaeang ka lebelo la 72 km/h e atamela sebaka seo terene e tšelang ho sona ha e ntse e letsa mololi ka maqhubu a 1600 Hz. Haeba lebelo la molumo moeeng e le 340 ms-1, joale maqhubu a mololi a utluoang ke molebeli oa sebaka seo terene e tšelang ho sona ke ….

A. 3600 Hz

B. 3400 Hz

C. 1800 Hz

D. 1700Hz

E. 1400Hz

Puisano

Hoa tsebahala hore:

Lebelo la mohlodi wa modumo (v_s) = 72 km/h = 20 m/s (ha ho bapisoa le sebaka se tsamaisang molumo)

Maqhubu a mohlodi wa modumo (f) = 1600 Hz

Lebelo la molumo moeeng (v) = 340 m/s

Lebelo la momameli (v_p) = 0 (lefela hobane momameli ha a sisinyehe)

E botsitsweng: maqhubu a modumo a utluwang ke molebedi (f')?

Karabo:

Karabo e nepahetseng ke D.

4. Teraka ea mollo e tsamaea ka lebelo la 20 ms^-1 ha o ntse o letsa siren ka maqhubu a 400 Hz (lebelo la molumo moeeng ke 300 ms^-1). Haeba enjene ea mollo e tloha hole le motho ea emeng ka thoko ho tsela, motho eo o tla utloa siren ka makhetlo a….

A. 375 Hz

B. 575 Hz

C. 600 Hz

D. 620 Hz

E. 725 Hz

Puisano

Hoa tsebahala hore:

v_s = 20 m/s (e ntle hobane koloi e suthela hole le momameli)

v_p = 0 (momameli ea khutsitseng ka thoko ho tsela)

f = 400 hz

v = 300 m/s

E botsitsoe: makhetlo ao molumo o utluoeng ka 'ona ?

Karabo:

Karabo e nepahetseng ke A.

5. Sebuela-hōle se tsoang toreng ea temoso se lla ka maqhubu a 670 Hz. Koloi e atamela toreng ka lebelo la 90 km/h. Haeba lebelo la molumo moeeng e le 335 m/s, joale maqhubu a molumo oa sebuela-hōle o utluoang ke mokhanni oa koloi ke...

A. 900 Hz

B. 840 Hz

C. 800 Hz

D. 750 Hz

E. 720 Hz

Puisano

Hoa tsebahala hore:

f = 670 hz

v_s = 0 (setšoantšo sa tora)

v_p = 90 km/h = 25 m/s (e ntle hobane momameli o atamela mohloli oa molumo)

v = 335 m/s

Potso: Molumo o utluoang ke mokhanni (f') o le makhetlo a makae?

Karabo:

Karabo e nepahetseng ke E.

6. Dini o ne a le tereneng e emeng A. Terene e 'ngoe (B) e ntse e leba A ka lebelo la 2 ms^-1 ha o ntse o letsa mololi ka maqhubu a 676 Hz. Haeba lebelo la modumo moyeng e le 340 ms^-1, ebe kgafetsa ya molodi wa terene B oo Dini a o utlwileng e ne e le….
A. 680 Hz

B. 676 Hz

C. 660 Hz

D. 656 Hz

E. 640 Hz

Puisano

Hoa tsebahala hore:

v_s = -2 m/s (terene e mpe B e atamela Dini le terene A

v_p = 0 (Pele tereneng e emeng)

f = 676 hz

v = 340 m/s

Botsitswe: Dini o utlwile maqhubu a terene ya B ka tsela efe?

Karabo:

Karabo e nepahetseng ke A.

7. Sebapali sa bolo ea maoto se matha ka lebelo la v_p ho ea ho moahloli ea neng a khutsitse ha a ntse a letsa mololi khafetsa ea f_sHaeba lebelo la moea sebakeng seo e le v, joale maqhubu a utluoang ke sebapali a hlophisitsoe joalo ka….

Puisano

Hoa tsebahala :

v_s = 0 (moahloli o khutsitse)

v_p = v_p (e ntle hobane e haufi le mohlodi wa modumo)

f = f_s

v = v

E botsitsoe : mokhoa oa makhetlo oo libapali tsa bolo ea maoto li o utloang ke ofe?

Jawab :

Karabo e nepahetseng ke A.

8. Ambulense A e tsamaya ka lebelo la 0,25 v ka morao ho sedan B e tsamayang ka lebelo la 0,2 v ka lehlakoreng le le leng le A. Ka nako eo, ambulense A e letsa siren ya yona ho 1.000 Hz. Haeba lebelo la modumo e le v, maqhubu a utluwang ke mokhanni wa sedan B ke…

A. 1.500 Hz

B. 1.250 Hz

C. 1.111 Hz

D. 1.067 Hz

E. 1.000 Hz

Puisano

Hoa tsebahala :

Maqhubu a mohlodi wa modumo (f) = 1.000 Hz

Lebelo la mohlodi wa modumo (v)_s) = -0,25 v (ha e bapisoa le seaplane se tsamaisang molumo)

Lebelo la molumo (v) = v

Lebelo la momameli (v)_p) = -0,2 v (ha e bapisoa le seaplane se tsamaisang molumo)

E botsitsoe : Khafetsa ea molumo o utluoang ke momameli (f')

Jawab :

Foromo ea phello ea Doppler:

Karabo e nepahetseng ke D.

9. Mohloli oa molumo o nang le maqhubu a 640 Hz o leba ho moshebelli ka lebelo la 20 m/s. Haeba lebelo la molumo moeeng e le 340 m/s 'me moshebelli a tloha mohloling oa molumo ka lebelo la 10 m/s, joale maqhubu a molumo o utluoang ke moshebelli ke…

A. 600 Hz

B. 660 Hz

C. 900 Hz

D. 980 Hz

E. 1300 Hz

Puisano

Hoa tsebahala :

Maqhubu a mohlodi wa modumo (f) = 640 Hz

Lebelo la mohlodi wa modumo (v_s) = -20 m/s (ha e bapisoa le moea e le sesebelisoa se tsamaisang molumo)

Lebelo la molumo (v) = 340 m/s (ha le bapisoa le moea e le sesebelisoa sa phetisetso ea molumo)

Lebelo la momameli (v_p) = -10 m/s (ha e bapisoa le moea e le sesebelisoa se tsamaisang molumo)

E botsitsoe : Khafetsa ea molumo o utluoang ke momameli (f')

Jawab :

Karabo e nepahetseng ke B.

10. Mohloli oa molumo o tsamaea ka lebelo la 60 m/s o siea moshebelli ka mor'a oona a tsamaea ka lehlakoreng le le leng le mohloli oa molumo ka lebelo la 10 m/s. Haeba lebelo la molumo moeeng e le 340 m/s 'me maqhubu a mohloli oa molumo e le 800 Hz, joale maqhubu a molumo o utluoang ke moshebelli ke…

A. 700 Hz

B. 800 Hz

C. 940 Hz

D. 960 Hz

E. 1.120 Hz

Puisano

Hoa tsebahala :

Maqhubu a mohlodi wa modumo (f) = 800 Hz

Lebelo la mohlodi wa modumo (v_s) = 60 m/s (ha e bapisoa le moea e le sesebelisoa se tsamaisang molumo)

Lebelo la molumo (v) = 340 m/s (ha le bapisoa le moea e le sesebelisoa sa phetisetso ea molumo)

Lebelo la momameli (v_p) = 10 m/s (ha e bapisoa le moea e le sesebelisoa se tsamaisang molumo)

E botsitsoe : Khafetsa ea molumo o utluoang ke momameli (f')

Jawab :

Karabo e nepahetseng ke A.

Matla a Molumo

11. Matla a molumo ntlheng ea P e bohōle ba limithara tse 3 ho tloha mohloling oa molumo ke 10^-4 watts/m²Ntlha ea R e bohōle ba limithara tse 300 ho tloha mohloling oa molumo. Haeba moeli oa matla I₀ = 10^-12 watts/m², ebe papiso ea maemo a matla lintlheng tsa P le R ke…

K. 1: 2

B. 2: 1

C. 2: 3

D. 2: 4

E. 3: 4

Puisano

Hoa tsebahala :

Matla a molumo ntlheng ea P (I)_P= 10^-4 W / limithara²

Sebaka sa ntlha P ho tloha mohloling oa molumo (r_P) = limithara tse 3

Sebaka sa ntlha R ho tloha mohloling oa molumo (r_R) = limithara tse 300

Matla a monyako (I)_o= 10^-12 Watt/m²

E botsitsoe Papiso ea maemo a matla lintlheng tsa P le R (TI)_P : IT_R)

Jawab :

Foromo ea kamano pakeng tsa matla le sebaka :

I_p r_p² = KE_R r_R²

Matla a molumo ho R :

(10^-4(3)²) = (Ke_R(300)²)

(10^-4)(9) = (Ke_R)(90000)

9: x 10^-4 = (Ke_R)(9 x 10⁴)

I_R = 9x10^-4 : 9 x 10^-4

I_R = 10^-8

Matla a molumo ntlheng ea R ke 10^-8 W / limithara².

Papiso ea TI lintlheng tsa P le R :

80 dB: 40 dB

2: 1

Karabo e nepahetseng ke B.

12. Matla a modumo ntlheng ya A e bohole ba mithara e le 1 ho tloha mohloding wa modumo ke 10^-7 W / limithara²Ntlha ea B e bohōle ba limithara tse 100 ho tloha mohloling oa molumo. Haeba matla a moeli a le 10^-12 W / limithara², papiso ea maemo a matla ho A le B ke…

K. 5: 3

B. 5: 1

C. 4: 5

D. 4: 3

E. 3: 1

Puisano

Hoa tsebahala :

Matla a molumo ntlheng ea A (I)_A= 10^-7 W / limithara²

Sebaka sa ntlha A ho tloha mohloling oa molumo (r)_A) = limithara tse 1

Sebaka sa ntlha B ho tloha mohloling oa molumo (r)_R) = limithara tse 100

Matla a monyako (I)_o= 10^-12 Watt/m²

E botsitsoe Papiso ea maemo a matla lintlheng tsa A le B (TI)_A : IT_B)

Jawab :

Foromo ea kamano pakeng tsa matla le sebaka :

I_A r_A² = KE_B r_B²

Matla a molumo ntlheng ea B :

(10^-7(1)²) = (Ke_B(100)²)

(10^-7)(1) = (Ke_B)(10.000)

1: x 10^-7 = (Ke_B)(1 x 10⁴)

I_B = 10^-7 : 10⁴

I_B = 10^-11

Matla a molumo ntlheng ea R ke 10^-11 W / limithara².

Papiso ea IT lintlheng tsa A le B :

50 dB: 10 dB

5: 1

Karabo e nepahetseng ke B.

13. Lintlha tsa A le B li na le sebaka sa 800 m le 400 m ka ho latellana ho tloha mohloling oa molumo. Haeba sebakeng sa A u utloa molumo o matla a 10^-3 W / limithara², joale papiso ea maemo a matla a lintlha A le B ke… (log 2 = 0,3 le I_o = 10^-12 W / limithara²)

K. 11: 15

B. 15: 11

C. 15: 16

D. 16: 11

E. 16: 15

Puisano

Hoa tsebahala :

Matla a molumo ntlheng ea A (I)_A= 10^-3 W / limithara²

Sebaka sa ntlha A ho tloha mohloling oa molumo (r)_A) = limithara tse 800

Sebaka sa ntlha B ho tloha mohloling oa molumo (r)_B) = limithara tse 400

Matla a monyako (I)_o= 10^-12 Watt/m²

Log 2 = 0,3

E botsitsoe Papiso ea maemo a matla lintlheng tsa A le B (TI)_A : IT_B)

Jawab :

Foromo ea kamano pakeng tsa matla le sebaka :

I_A r_A² = KE_B r_B²

Matla a molumo ntlheng ea B :

(10^-3(800)²) = (Ke_B(400)²)

(10^-3)(640.000) = (Ke_B)(160.000)

(10^-3)(64) = (Ke_B)(16)

(10^-3)(4) = (Ke_B)(1)

I_B = 4x10^-3 : 1

I_B = 4x10^-3

Matla a molumo ntlheng ea B ke 4 x 10^-3 W / limithara².

Karolelano ea TI lintlheng tsa P le R ke:

90 dB: 96 dB

15: 16

Karabo e nepahetseng ke C.

Matla le maemo a matla a molumo

14. Tafole ea maemo a matla bakeng sa mohloli o mong le o mong oa molumo.

Mohloli oa molumo	Boemo ba Matla a Molumo (TI)
Molumo oa linonyana tse llang	80 dB
Sirene ea ambulense	100 dB
Sealuma (lehalima)	160 dB

Enjene ea koloi e hlahisa boemo ba matla a molumo oa TI = 70 dB (I_o = 10^-12 Watt m^-2). E le hore molumo oa enjene o hlahise boemo ba matla bo lekanang le molumo oa siren ea ambulense, palo ea lienjene tsa likoloi tse hlokahalang ke….

Mochini oa A. 20.00
Mochini oa B. 30.00
Mechini ea C. 100.0
D. Mechini e 1.000
Mechini e 3.000 ea E.

Puisano
Hoa tsebahala :
Koloi ea TI = 70 dB
Ambulense TI = 100 dB
I_o = 10^-12 Watt/m²
E botsitsoe : IT ea koloi e lokela ho lekana le IT ea ambulense ka lienjine tse kae tsa koloi?
Jawab :

Ambulense TI = koloi 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
Karabo e nepahetseng ke D.

15. Mohloli oa molumo o na le boemo ba matla ba 60 dB (I_o = 10 ^{- 12} watt m^-2). Ha mehlodi e 100 e tšoanang ea molumo e utloahala ka nako e le 'ngoe, boemo ba matla a molumo bo hlahisoang ke….

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

Puisano
Hoa tsebahala :
TI = 60 dB
I_o = 10^-12 W / limithara²
x = 100
E botsitsoe : Mohloli oa molumo oa TI 100?
Jawab :
Mehloli ea molumo ea TI 100 = Mochini oa 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
Karabo e nepahetseng ke B.

Phello ea Doppler
16. Sebapali sa bolo ea maoto se matha ka lebelo v_p ho ea ho moahloli ea neng a khutsitse ha a ntse a letsa mololi khafetsa ea f_sHaeba lebelo la moea sebakeng seo e le v, joale maqhubu a utluoang ke sebapali a hlophisitsoe joalo ka….

Puisano
Hoa tsebahala :
v_s = 0 (moahloli o khutsitse)
v_p = v_p (e ntle hobane e haufi le mohlodi wa modumo)
f = f_s
v = v
E botsitsoe : mokhoa oa makhetlo oo libapali tsa bolo ea maoto li o utloang ke ofe?
Jawab :

Karabo e nepahetseng ke A.

Mohloli oa lipotso:

Lipotso tsa Fisiks tsa Tlhahlobo ea Naha bakeng sa Sekolo se Phahameng sa Thuto e Phahameng/Sekolo se Phahameng sa Mosebetsi