9 Ngā Tauira o ngā Pātai mō te Kaha Coulomb
1. E toru ngā kawenga kua whakaritea pērā i te pikitia i raro nei. Ko te kaha Coulomb e pāngia ana e te utu B ko …. (k = 9 x 109 Nm2C-2, 1 μC = 10-6 C)

A. 09 x 10 1 N hei utu C
B. 09 x 10 1 N hei utu i a A
C. 18 x 10 1 N hei utu C
D. 18 x 10 1 N hei utu i a A
E. 36 x 10 1 N hei utu C
Kōrero
E mōhiotia ana :
q A = 10 µC = 10 x 10 -6 C = 10 -5 Coulombs
q B = 10 µC = 10 x 10 -6 = 10 -5 Ngā Coulomb
q C = 20 µC = 20 x 10 -6 = 2 x 10 -5 Ngā Coulomb
r AB = 0,1 mita = 10 -1 mita
r BC = 0,1 mita = 10 -1 mita
k = 9 x 10 9 Nm 2 C −2
I pātaihia : Te kaha Coulomb i pāngia e te utunga B
Whakautu :
E rua ngā kaha Coulomb, arā, ngā kaha hiko e pā ana ki te utu B, arā, ko te kaha Coulomb i waenganui i ngā utu A me B (F AB ) me te kaha Coulomb i waenganui i ngā utu B me C (F BC ). Ko te kaha Coulomb e pāngia ana e te utu B ko te hua o F AB me F BC.
Te kaha Coulomb i waenganui i ngā utu A me B:

He pai te utu A, ā, he pai te utu B, nō reira ka anga a F AB ki te utu C.
Te kaha Coulomb i waenganui i ngā utu B me C:

He pai te utu B, ā, he pai te utu C, nō reira ka anga a F BC ki te utu A.
Te kaha Coulomb e pāngia ana e te utu B:
F B = F BC – F AB = 180-90 = 90 N
Ko te rahi o te kaha Coulomb e pāngia ana e te utu B (F B ) he 90 Newton. Ko te ahunga o F B he rite ki te ahunga o F BC , arā, ki te utu A.
Ko te whakautu tika ko B.
2. Ko te rahi me te ahunga o te kaha Coulomb i runga i te utu B ko... ( k = 9 x 10 9 Nm 2 C −2 , 1 μC = 10 −6 C)
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A. 2,5 k Q 2 r -2 ki te taha maui
B. 2,5 k Q 2 r -2 ki te taha matau
C. 2 k Q 2 r -2 ki te taha maui
D. 2 k Q 2 r -2 ki te taha matau
E. 1 k Q 2 r -2 ki te taha maui
Kōrero
E mōhiotia ana :
Utu A (q A ) = +Q
Utu B (q B ) = -2Q
Utu C (q C ) = -Q
Ko te tawhiti i waenganui i ngā utu A me B (r AB ) = r
Ko te tawhiti i waenganui i ngā utu B me C (r BC ) = 2r
k = 9 x 10 9 Nm 2 C −2
I pātaihia : te rahi me te ahunga o te kaha Coulomb i runga i te utu B
Whakautu :
Te kaha Coulomb i waenganui i te utu A me te utu B:

He pai te utu A, he kino te utu B, nō reira ko te ahunga o F AB e anga atu ana ki te utu A.
Te kaha Coulomb i waenganui i te utu B me te utu C:
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He kino te utu B, ā, he kino te utu C, nō reira ko te ahunga o F BC e anga atu ana ki te utu A.
Ko te kaha hua e pā ana ki te utu B:
F = F AB + F BC = 2 k Q 2 /r 2 + 0,5 k Q 2 /r 2 = 2,5 k Q 2 /r 2 = 2,5 k Q 2 r -2
Ko te ahunga o te kaha Coulomb e anga ana ki te utunga A, ki maui rānei.
Ko te whakautu tika ko A.
3. E rua ngā utu hiko e whakanohoia motuhaketia ana e ai ki te pikitia. Ko te utu i A he 8 µC, ā, ko te kaha kukume e pā ana ki ngā utu e rua he 45 N. Mena ka nekehia te utu A ki te taha matau mā te 1 cm, ā, ko k = 9.10 9 Nm 2 .C -2 , ko te kaha kukume e pā ana ki ngā utu e rua ko…
A. 45 N
B. 60 N
C. 80 N
D. 90 N
E. 120 N
Kōrero
E mōhiotia ana :
Utu hiko i A (q A ) = 8 µC = 8 x 10 -6 Coulombs
Ko te kaha hiko i waenganui i ngā utu e rua (F) = 45 Newton
Ko te tawhiti i waenganui i ngā utu e rua (r AB ) = 4 cm = 0,04 mita = 4 x 10 -2 mita
Pūmau (k) = 9 x 10 9 Nm 2 .C -2
Pātai : Ko te kaha hiko i waenganui i ngā utu e rua mēnā ka nekehia te utu A ki te taha matau mā te 1 cm, 0,01 mita rānei
Whakautu :
Tuatahi, tatauhia te utu hiko i B, kātahi ka tatau i te kaha hiko i waenganui i ngā utu hiko e rua, mēnā ka nekehia te utu hiko i A ki te taha matau mā te 1 cm.
Te utu hiko i B :
Tātai Te ture a Coulomb :
F = k (q A )(q B ) / r 2
F r 2 = k (q A )(q B )
q B = F r 2 / k (q A )
Utu hiko i B :
q B = (45)(4 x 10 -2 ) 2 / (9 x 10 9 )(8 x 10 -6 )
q B = (45)(16 x 10 -4 ) / 72 x 10 3
q B = (720 x 10 -4 ) / (72 x 10 3 )
q B = 10 x 10 -7 Ngā Kuromi
Te kaha hiko i waenganui i ngā utu hiko A me B :
Ki te nekehia te utu i A ki te taha matau mā te 1 cm, ka noho te tawhiti i waenganui i ngā utu e rua hei 3 cm = 0,03 mita = 3 x 10 -2 mita
F = k (q A )(q B ) / r 2
W = (9 x 10 9 )(8 x 10 -6 )(10 x 10 -7 ) / (3 x 10 -2 ) 2
F = (9 x 10 9 )(80 x 10 -13 ) / (9 x 10 -4 )
F = (1 x 10 9 )(80 x 10 -13 ) / (1 x 10 -4 )
F = (80 x 10 -4 ) / (1 x 10 -4 )
F = 80 Newton
Ko te whakautu tika ko C.
4. E rua ngā utu hiko P me Q, he 10 cm te tawhiti, ka pāngia e te kaha kukume o te 8 N. Mēnā ka nekehia te utu Q ki te 5 cm ki te utu P (1 µC = 10 -6 C me te k = 9 x 10 9 Nm 2 .C -2 ), ko te kaha hiko e puta ana ko...
A. 8 N
B. 16 N
C. 32 N
D. 40 N
E. 56 N
Kōrero
E mōhiotia ana :
Ko te tawhiti i waenganui i ngā utu P me Q (r PQ ) = 10 cm = 0,1 m = 1 x 10 -1 m
Ko te kaha hiko i waenganui i ngā utu P me Q (F) = 8 N
Utu hiko Q (q Q ) = 40 µC = 40 x 10 -6 C
Pūmau (k) = 9 x 10 9 Nm 2 .C -2
Pātai : Ko te kaha hiko i waenganui i ngā utu P me Q mēnā ka nekehia te utu Q kia 5 cm te anga atu ki te utu P
Whakautu :
Tuatahi, tatauhia te utu hiko P, kātahi ka tatauhia te kaha hiko i waenganui i ngā utu hiko e rua, mēnā ka nekehia te utu hiko Q kia 5 cm te anga atu ki te utu P.
Utu hiko P :
q P = F r 2 / k (q Q )
q P = (8)(1 x 10 -1 ) 2 / (9 x 10 9 )(40 x 10 -6 )
q P = (8)(1 x 10 -2 ) / 360 x 10 3
q P = (8 x 10 -2 ) / (36 x 10 4 )
q P = (1 x 10 -2 ) / (4,5 x 10 4 )
q P = (1/4,5) x 10 -6 Coulomb
Te kaha hiko i waenganui i ngā utu hiko P me Q :
Ki te nekehia te utu i Q ki te taha maui mā te 5 cm, ka noho te tawhiti i waenganui i ngā utu e rua hei 5 cm = 0,05 mita = 5 x 10 -2 mita
F = k (q P )(q Q ) / r 2
F = (9 x 10 9 )( (1/4,5) x 10 -6 )(40 x 10 -6 ) / (5 x 10 -2 ) 2
F = (2 x 10 3 )(40 x 10 -6 ) / (25 x 10 -4 )
F = (80 x 10 -3 ) / (25 x 10 -4 )
F = 3,2 x 10 1
F = 32 Newton
Ko te whakautu tika ko C.
5. Tirohia te ahua e whai ake nei o ngā utu hiko. Ko te kaha hiko e pāngia ana e te utu q B ko 8 N (1 µC = 10 -6 C) me (k = 9.10 9 Nm 2 .C -2 ). Mena ka nekehia te utu q B ki te 4 cm mai i A, ko te kaha hiko e pāngia ana e q B ko…
A. 2 N
B. 4 N
C. 6 N
D. 8 N
E. 10 N
Kōrero
E mōhiotia ana :
Ko te tawhiti i waenganui i ngā utu A me B (r AB ) = 2 cm = 0,02 m = 2 x 10 -2 m
Ko te kaha hiko i waenganui i ngā utu A me B (F) = 8 N
Utu hiko A (q A ) = 2 µC = 2 x 10 -6 C
Pūmau (k) = 9 x 10 9 Nm 2 .C -2
Pātai : Ko te kaha hiko i waenganui i ngā utu A me B mēnā he 4 cm te tawhiti i waenganui i ngā utu e rua.
Whakautu :
Tuatahi, tatauhia te utu hiko B, kātahi ka tatauhia te kaha hiko i waenganui i ngā utu hiko e rua mēnā ko te tawhiti i waenganui i ngā utu hiko e rua he 4 cm = 0,04 mita = 4 x 10 -2 mita.
Utu hiko B :
q B = F r 2 / k (q A )
q B = (8)(2 x 10 -2 ) 2 / (9 x 10 9 )(2 x 10 -6 )
q B = (8)(4 x 10 -4 ) / (18 x 10 3 )
q B = (32 x 10 -4 ) / (18 x 10 3 )
q B = (32/18) x 10 -7
q B = (16/9) x 10 -7 Ngā Kuoromu
Te kaha hiko i waenganui i ngā utu A me B :
F = k (q A )(q B ) / r 2
F = (9 x 10 9 )(2 x 10 -6 )( (16/9) x 10 -7 ) / (4 x 10 -2 ) 2
W = (18 x 10 3 )( (16/9) x 10 -7 ) / (16 x 10 -4 )
F = (2 x 10 3 )(16 x 10 -7 ) / (16 x 10 -4 )
F = (2 x 10 3 )(1 x 10 -7 ) / (1 x 10 -4 )
F = (2 x 10 -4 ) / (1 x 10 -4 )
F = 2 Newton
Ko te whakautu tika ko A.
6. E toru ngā utu hiko kei ngā kokonga o te tapatoru ABC, ko te roa o te taha AB = BC = 20 cm, ā, he rite tonu te rahi o te utu (q = 2µC) ki te pikitia kei te taha (k = 9.10 9 Nm 2 .C -2 , 1 µ = 10 -6 ). Ko te rahi o te kaha hiko e pā ana ki te pūwāhi B ko….
A. 0,9√3 N
B. 0,9√2 N
C. 0,9 N
D. 0,81 N
E. 0,4 N
Kōrero
E mōhiotia ana:
Utu i te pūwāhi A (q A ) = 2 µC = 2 x 10 -6 Coulomb
Utu i te pūwāhi B (q B ) = 2 µC = 2 x 10 -6 Coulomb
Utu i te pūwāhi C (q C ) = 2 µC = 2 x 10 -6 Coulomb
Te tawhiti mai i B ki C (r BC ) = 20 cm = 0,2 mita = 2 x 10 -1 mita
Te tawhiti o B ki A (r BA ) = 20 cm = 0,2 mita = 2 x 10 -1 mita
k = 9.10 9 Nm 2 .C -2
Pātai: Te rahi o te kaha hiko e pā ana ki te pūwāhi B
Whakautu:
Ko te kaha hiko i waenganui i ngā utu i ngā pūwāhi B me C:
F BC = k (q B )(q C ) / r BC 2
F BC = (9 x 10 9 )(2 x 10 -6 )(2 x 10 -6 ) / (2 x 10 -1 ) 2
F BC = (9 x 10 9 )(4 x 10 -12 ) / (4 x 10 -2 )
F BC = (36 x 10 -3 ) / (4 x 10 -2 )
F BC = 9 x 10 -1
F BC = 0,9 Newton
He pai te utu hiko i ngā pūwāhi B me C, nō reira ko te ahunga o te kaha hiko F BC kei te taha mauī, atu i te pūwāhi C.
Ko te kaha hiko i waenganui i ngā utu i ngā pūwāhi B me A:
F BA = k (q B )(q A ) / r BA 2
F BA = (9 x 10 9 )(2 x 10 -6 )(2 x 10 -6 ) / (2 x 10 -1 ) 2
F BA = (9 x 10 9 )(4 x 10 -12 ) / (4 x 10 -2 )
F BA = (36 x 10 -3 ) / (4 x 10 -2 )
F BA = 9 x 10 -1
F BA = 0,9 Newton
He pai te utu hiko i ngā pūwāhi B me A, nō reira ko te ahunga o te kaha hiko F BA kei raro, kei tawhiti atu i te pūwāhi A.
Ka hanga he koki matau ngā kaha hiko e rua, nō reira ka tatauhia te kaha hiko e puta mai ana i te pūwāhi B mā te whakamahi i te tātai Pythagoras.

Ko te whakautu tika ko B.
7. Tirohia te pikitia e whai ake nei!
E toru ngā utu Q1 , Q2 , me Q3 kei ngā pito o te tapatoru matau ABC. Ko te roa o AB = BC = 30 cm. Mēnā ko k = 9.10 9 Nm2 .C -2 me 1 µ = 10 -6 , ko te kaha Coulomb i puta mai i runga i te utu Q1 ko ….
A. 1 N
B. 5 N
C. 7 N
D. 10 N
E. 12 N
Kōrero
E mōhiotia ana:
Utu i te pūwāhi A (q A ) = 3 µC = 3 x 10 -6 Coulomb
Utu i te pūwāhi B (q B ) = -10 µC = -10 x 10 -6 Coulomb
Utu i te pūwāhi C (q C ) = 4 µC = 4 x 10 -6 Coulomb
Te tawhiti mai i B ki C (r BC ) = 30 cm = 0,3 mita = 3 x 10 -1 mita
Te tawhiti o B ki A (r BA ) = 30 cm = 0,3 mita = 3 x 10 -1 mita
k = 9.10 9 Nm 2 .C -2
Pātai: Te kaha Coulomb hua i te pūwāhi B
Whakautu:
Ko te kaha hiko i waenganui i ngā utu i ngā pūwāhi B me C:
F BC = k (q B )(q C ) / r BC 2
F BC = (9 x 10 9 )(10 x 10 -6 )(4 x 10 -6 ) / (3 x 10 -1 ) 2
F BC = (9 x 10 9 )(40 x 10 -12 ) / (9 x 10 -2 )
F BC = (360 x 10 -3 ) / (9 x 10 -2 )
F BC = 40 x 10 -1
F BC = 4 Newton
He kino te utu hiko i te pūwāhi B, ā, he pai te utu hiko i te pūwāhi C, nō reira ko te ahunga o te kaha hiko F BC kei te taha matau ki te pūwāhi C.
Ko te kaha hiko i waenganui i ngā utu i ngā pūwāhi B me A:
F BA = k (q B )(q A ) / r BA 2
F BA = (9 x 10 9 )(10 x 10 -6 )(3 x 10 -6 ) / (3 x 10 -1 ) 2
F BA = (9 x 10 9 )(30 x 10 -12 ) / (9 x 10 -2 )
F BA = (270 x 10 -3 ) / (9 x 10 -2 )
F BA = 30 x 10 -1
F BA = 3 Newton
He kino te utu hiko i te pūwāhi B, ā, he pai te utu hiko i te pūwāhi A, nō reira ko te ahunga o te kaha hiko F BA kei runga, e anga atu ana ki te pūwāhi A.
Ka hanga he koki matau ngā kaha hiko e rua, nō reira ka tatauhia te kaha hiko e puta mai ana i te pūwāhi B mā te whakamahi i te tātai Pythagoras.

Ko te whakautu tika ko B.
8. E toru ngā utu hiko kei ngā kokonga o te tapatoru ABC, ko te roa o te taha AB = BC = 20 cm, ā, ko te rahi o te utu (q = 2µC) rite tonu ki te pikitia kei te taha (k = 9.109 Nm2.C-2, 1 µ = 10-6Te rahi o te kaha hiko
ko te mahi i te pūwāhi B ko….
- 0,9√3 N
- 0,9√2 N
- 0,9 N
- 0,81 N
- 0,4 N
Kōrero
E mōhiotia ana:
Ko te utu i te pūwāhi A (qA) = 2 µC = 2 x 10-6 Coulomb
Ko te utu i te pūwāhi B (qB) = 2 µC = 2 x 10-6 Coulomb
Ko te utu i te pūwāhi C (qC) = 2 µC = 2 x 10-6 Coulomb
Te tawhiti mai i B ki C (rBC) = 20 henimita = 0,2 mita = 2 x 10-1 mita
Te tawhiti mai i B ki A (rBA) = 20 henimita = 0,2 mita = 2 x 10-1 mita
k = 9.109 Nm2.C-2
I pātaihia: Te rahi o te kaha hiko e pā ana ki te pūwāhi B
Whakautu:
Ko te kaha hiko i waenganui i ngā utu i ngā pūwāhi B me C:
FBC = k (qB)(qC) / rBC2
FBC = (9 x 109)(2 x 10-6)(2 x 10-6) / (2 x 10-1)2
FBC = (9 x 109)(4 x 10-12) / (4 x 10-2)
FBC = (36 x 10-3) / (4 x 10-2)
FBC = 9x10-1
FBC = 0,9 Niutona
He pai te utu hiko i ngā pūwāhi B me C, nō reira ko te ahunga o te kaha hiko F koBC ki te taha maui, atu i te pūwāhi C.
Ko te kaha hiko i waenganui i ngā utu i ngā pūwāhi B me A:
FBA = k (qB)(qA) / rBA2
FBA = (9 x 109)(2 x 10-6)(2 x 10-6) / (2 x 10-1)2
FBA = (9 x 109)(4 x 10-12) / (4 x 10-2)
FBA = (36 x 10-3) / (4 x 10-2)
FBA = 9x10-1
FBA = 0,9 Niutona
He pai te utu hiko i ngā pūwāhi B me A, nō reira ko te ahunga o te kaha hiko F koBA ki raro, ki tawhiti atu i te pūwāhi A.
Ka hanga he koki matau ngā kaha hiko e rua, nō reira ka tatauhia te kaha hiko e puta mai ana i te pūwāhi B mā te whakamahi i te tātai Pythagoras.
Ko te whakautu tika ko B.
9. Tirohia te pikitia e whai ake nei!
E toru ngā utu Q1,Q2, me Q3 kei te pito o te tapatoru matau ABC. Ko te roa o AB = BC = 30 cm. E mōhiotia ana
k = 9.109 Nm2.C-2 ā, 1 µ = 10-6 kātahi ka puta te kaha Coulomb i runga i te utu Q1 ko….
- 1 N
- 5 N
- 7 N
- 10 N
- 12 N
Kōrero
E mōhiotia ana:
Ko te utu i te pūwāhi A (qA) = 3 µC = 3 x 10-6 Coulomb
Ko te utu i te pūwāhi B (qB) = -10 µC = -10 x 10-6 Coulomb
Ko te utu i te pūwāhi C (qC) = 4 µC = 4 x 10-6 Coulomb
Te tawhiti mai i B ki C (rBC) = 30 henimita = 0,3 mita = 3 x 10-1 mita
Te tawhiti mai i B ki A (rBA) = 30 henimita = 0,3 mita = 3 x 10-1 mita
k = 9.109 Nm2.C-2
I pātaihia: Te kaha Coulomb hua i te pūwāhi B
Whakautu:
Ko te kaha hiko i waenganui i ngā utu i ngā pūwāhi B me C:
FBC = k (qB)(qC) / rBC2
FBC = (9 x 109)(10 x 10-6)(4 x 10-6) / (3 x 10-1)2
FBC = (9 x 109)(40 x 10-12) / (9 x 10-2)
FBC = (360 x 10-3) / (9 x 10-2)
FBC = 40x10-1
FBC = 4 Niutona
He kino te utu hiko i te pūwāhi B, ā, he pai te utu hiko i te pūwāhi C, nō reira ko te ahunga o te kaha hiko F koBC ki te taha matau ki te pūwāhi C.
Ko te kaha hiko i waenganui i ngā utu i ngā pūwāhi B me A:
FBA = k (qB)(qA) / rBA2
FBA = (9 x 109)(10 x 10-6)(3 x 10-6) / (3 x 10-1)2
FBA = (9 x 109)(30 x 10-12) / (9 x 10-2)
FBA = (270 x 10-3) / (9 x 10-2)
FBA = 30x10-1
FBA = 3 Niutona
He kino te utu hiko i te pūwāhi B, ā, he pai te utu hiko i te pūwāhi A, nō reira ko te ahunga o te kaha hiko F koBA ki runga ki te pūwāhi A.
Ka hanga he koki matau ngā kaha hiko e rua, nō reira ka tatauhia te kaha hiko e puta mai ana i te pūwāhi B mā te whakamahi i te tātai Pythagoras.
Ko te whakautu tika ko B.
Pūtake pātai:
Ngā Pātai Ahupūngao Whakamātautau ā-Motu mō te Kura Tuarua/Kura Tuarua Mahi-ā-ringa