Lub zog electrostatic - teeb meem thiab kev daws teeb meem
1. Yog tias lub zog hluav taws xob zoo li qub yog 144 N, qhov deb ntawm ob qho nqi yog dab tsi ... (1 μC = 10 -6 C thiab k = 9.10 9 Nm 2 .C -2 )
Paub:
Lub zog hluav taws xob (F 12 ) = 144 N
Them 1 (q 1 ) = 10 μC = 10 x 10 -6 C
Them 2 (q 2 ) = 4 μC = 4 x 10 -6 C
Qhov ruaj khov (k) = 9 x 10 9 Nm 2 .C -2
C = Coulomb, N = Newton, m = 'meter'
Xav tau: Qhov deb ntawm ob qho nqi (r)
Tshuaj:
Kev sib npaug ntawm Coulomb txoj cai :
F = lub zog hluav taws xob zoo li qub, k = Coulomb's constant, q = lub zog hluav taws xob, r = qhov deb ntawm ob lub zog
Qhov nrug ntawm ob qho nqi (r) = 5 x 10 -2 meters = 5 x 10 -2 x 10 2 cm = 5 cm.
2. Ob lub nqi sib cais los ntawm qhov deb ntawm r . Yog tias lub zog hluav taws xob zoo li qub yog 3.6 N, qhov deb ntawm ob lub nqi yog dab tsi (1 μC = 10 -6 C thiab k = 9.10 9 Nm 2 .C -2 )
Paub:
Lub zog hluav taws xob (F 12 ) = 3.6 N
Them 1 (q 1 ) = 9 μC = 9 x 10 -6 C
Them 2 (q 2 ) = 4 μC = 4 x 10 -6 C
Coulomb tus nqi tas mus li (k) = 9 x 10 9 Nm 2 .C -2
C = Coulomb, N = Newton, m = 'meter'
Xav tau: Qhov deb ntawm ob qho nqi (r)
Tshuaj:
Qhov nrug ntawm ob qho tib si (r) = 0.3 m = 0.3 x 100 cm = 30 cm.
3. Peb lub ntsiab lus them raws li qhia hauv daim duab hauv qab no. Lub zog hluav taws xob zoo li qub ntawm qhov chaw A (k = 9.10 9 Nm 2 .C -2 ; 1 μ = 10 -6 ) yog dab tsi?
Paub:
them Ib (q)A) = -2 μC = -2 x 10-6 C
Tus nqi B (qB ) = 8 μC = 8 x 10 -6 C
Them C (q C ) = 4,5 μC = 4,5 x 10 -6 C
Coulomb tus nqi tas mus li (k) = 9 x 10 9 Nm 2 .C -2
Qhov nrug ntawm cov nqi A thiab B (r AB ) = 4 cm = 4 x 10 -2 m
Qhov nrug ntawm cov nqi A thiab C (r AC ) = 3 cm = 3 x 10 -2 m
C = Coulomb, N = Newton, m = 'meter'
Xav tau: Lub zog hluav taws xob static ntawm qhov chaw A
Tshuaj:
Kev sib npaug ntawm Coulomb txoj cai:
F = lub zog hluav taws xob zoo li qub , k = Coulomb tus nqi tas mus li , q = lub zog hluav taws xob , r = qhov deb ntawm ob qho tib si
Lub zog hluav taws xob static ntawm qhov chaw A:
4. Cov nqi peb-taw tes raws li qhia hauv daim duab hauv qab no. Lub zog Coulomb uas Charge B ntsib yog dab tsi (k = 9.10 9 Nm 2 .C -2 ; 1 μC = 10 -6 C ).
Paub:
q A = 10 µC = 10 x 10 -6 C = 10 -5 Coulombs
q B = 10 µC = 10 x 10 -6 = 10 -5 Coulombs
q C = 20 µC = 20 x 10 -6 = 2 x 10 -5 Coulombs
r AB = 0.1 meter = 10 -1 m
r BC = 0.1 meter = 10 -1 m
k = 9 x 10 9 Nm 2 C −2
Xav Tau: Lub zog Coulomb uas Charge B ntsib
Tshuaj:
Muaj ob lub zog coulomb ua rau ntawm tus nqi B, lub zog Coulomb ntawm cov nqi A thiab B (F AB ) thiab lub zog Coulomb ntawm cov nqi B thiab C (F BC ). Lub zog Coulomb uas tus nqi B ntsib yog lub zog net ntawm F AB thiab F BC.
Lub zog Coulomb ntawm cov nqi A thiab B:
Tus nqi A kos npe zoo thiab tus nqi B kos npe zoo kom F AB taw tes rau tus nqi C.
Lub zog Coulomb ntawm cov nqi B thiab C:
Tus nqi B kos npe zoo thiab tus nqi C kos npe zoo yog li F BC taw tes rau tus nqi A.
Lub zog Coulomb uas raug los ntawm tus nqi B:
F B = F BC – F AB = 180 – 90 = 90 N
Lub zog Coulomb uas raug los ntawm lub zog B (F B ) yog 90 Newtons. Lub zog ntawm F B yog tib yam li lub zog ntawm F BC taw rau lub zog A.
5. Txheeb xyuas qhov loj thiab kev coj ntawm Coulomb lub zog ntawm lub zog B ( k = 9 x 10 9 Nm 2 C −2 , 1 μC = 10 −6 C).
Paub:
Tus nqi A (q A ) = +Q
Tus nqi B (q B ) = -2Q
Them C (q C ) = -Q
Qhov nrug ntawm cov nqi A thiab B (r AB ) = r
Qhov nrug ntawm cov nqi B thiab C (r BC ) = 2r
k = 9 x 10 9 Nm 2 C −2
Xav tau: Qhov loj thiab kev coj ntawm Coulomb lub zog ntawm tus nqi B
Tshuaj:
Lub zog Coulomb ntawm cov nqi A thiab B:
Tus nqi A yog qhov zoo thiab tus nqi B yog qhov tsis zoo yog li qhov kev taw qhia ntawm F AB taw rau tus nqi A.
Lub zog Coulomb ntawm tus nqi B thiab tus nqi C:
Tus nqi B yog qhov tsis zoo thiab tus nqi C yog qhov tsis zoo yog li qhov kev taw qhia ntawm F BC taw rau tus nqi A.
Lub zog net force ntawm tus nqi B:
F = FAB +FBC = 2 k Q2/r2 + 0.5 k Q2/r2 = 2.5 k Q2/r2 = 2.5 k Q2 r-2
Kev taw qhia ntawm lub zog taw tes rau them A lossis mus rau sab laug.
