Piv txwv cov lus nug tham txog hluav taws xob zoo li qub
Pendahuluuan
Hluav taws xob zoo li qub yog ib qho xwm txheej uas peb feem ntau ntsib hauv peb lub neej txhua hnub. Txij li qhov kev paub txog kev raug hluav taws xob me me thaum kov lub qhov rooj mus rau qhov cuam tshuam ntawm cov plaub hau sawv ntawm qhov kawg thaum txhuam nrog lub zuag yas, txhua yam tuaj yeem piav qhia los ntawm cov ntsiab cai ntawm hluav taws xob zoo li qub. Tsab xov xwm no yuav tham txog ntau qhov piv txwv ntawm cov teeb meem hluav taws xob zoo li qub, piav qhia txog cov ntsiab lus tseem ceeb thiab siv cov kev cai lij choj siv tau.
Kev Nkag Siab Txog Hluav Taws Xob Static
Hluav taws xob zoo li qub yog qhov sib sau ua ke ntawm cov hluav taws xob ntawm qhov chaw ntawm ib yam khoom. Qhov no tshwm sim vim yog kev hloov pauv ntawm cov hluav taws xob los ntawm ib yam khoom mus rau lwm yam, feem ntau yog los ntawm kev sib txhuam, xws li thaum lub npas raug txhuam rau ntawm cov plaub hau. Lub zog uas tshwm sim los ntawm cov hluav taws xob no yog tswj hwm los ntawm Coulomb txoj cai.
Txoj cai Coulomb hais tias lub zog ntawm ob yam khoom uas raug them yog sib npaug rau qhov sib npaug ntawm qhov loj ntawm cov nqi sib xws thiab sib npaug rau qhov sib npaug ntawm qhov deb ntawm lawv. Cov qauv lej rau txoj cai no yog:
\[ F = k \frac{{|q_1 q_2|}}{{r^2}} \]
Qhov twg:
- \( F \) yog lub zog ntawm ob lub nqi,
- \( k \) yog Coulomb tas li (\( 8.99 \times 10^9 \, N \cdot m^2 / C^2 \)),
- \( q_1 \) thiab \( q_2 \) yog qhov loj ntawm cov nqi hluav taws xob, thiab
-\(r\) yog qhov deb ntawm ob lub nqi.
Cov Lus Nug thiab Kev Sib Tham Piv Txwv
Lo Lus Nug 1: Xam Coulomb Lub Zog Hluav Taws Xob
Ob lub zog hluav taws xob uas muaj qhov loj \( 5 \, \mu C \) thiab \( -3 \, \mu C \) raug muab tso rau ntawm qhov deb ntawm 20 cm. Xam lub zog hluav taws xob ntawm ob lub zog hluav taws xob!
Kev Sib Tham:
Ua ntej, hloov cov chav ntawm tus nqi thiab qhov deb mus rau hauv lub kaw lus thoob ntiaj teb (SI):
– \( q_1 = 5 \, \mu C = 5 \times 10^{-6} \, C \)
– \( q_2 = -3 \, \mu C = -3 \times 10^{-6} \, C \)
– \( r = 20 \, cm = 0.2 \, m \)
Siv Coulomb txoj cai los xam lub zog:
\[ F = k \frac{{|q_1 q_2|}}{{r^2}} \]
Hloov cov nqi uas paub lawm:
\[ F = \left( 8.99 \times 10^9 \frac{N \cdot m^2}{C^2} \right) \frac{{|5 \times 10^{-6} \, C \times (-3 \times 10^{-6} \, C)|}}{{(0.2 \, m)^2}} \]
\[ F = \left( 8.99 \times 10^9 \right) \frac{{15 \times 10^{-12}}}{{0.04}} \]
\[ F = \sab laug (8.99 \times 10^9 \right) \times 3.75 \times 10^{-10} \]
\[ F = 3.37 \, N \]
Lub zog ntawm ob lub nqi yog 3.37 N thiab vim tias ib qho ntawm cov nqi yog qhov tsis zoo, lub zog no yog qhov nyiam.
Lo Lus Nug 2: Qhov Cuam Tshuam ntawm Qhov Deb ntawm Coulomb Force
Ob lub zog \( +4 \, \mu C \) thiab \( +6 \, \mu C \) raug muab tso rau ntawm qhov deb ntawm 0.1 m. Yog tias qhov deb ntawm ob lub zog raug nce mus txog 0.2 m, txiav txim siab seb lub zog Coulomb hloov pauv li cas!
Kev Sib Tham:
Ua ntej, xam lub zog ntawm qhov deb pib \( 0.1\, m\):
– \( q_1 = 4 \, \mu C = 4 \times 10^{-6} \, C \)
– \( q_2 = 6 \, \mu C = 6 \times 10^{-6} \, C \)
– \( r_1 = 0.1 \, m \)
\[ F_1 = k \frac{{|q_1 q_2|}}{{r_1^2}} \]
Hloov cov nqi uas paub lawm:
\[ F_1 = \left( 8.99 \times 10^9 \right) \frac{{24 \times 10^{-12}}}{{(0.1)^2}} \]
\[ F_1 = \sab laug ( 8.99 \times 10^9 \right) \times 2.4 \times 10^{-10} \]
\[ F_1 = 2.1576 \, N \]
Tam sim no, xam lub zog ntawm qhov deb tshiab \( 0.2 \, m \):
– \( r_2 = 0.2 \, m \)
\[ F_2 = k \frac{{|q_1 q_2|}}{{r_2^2}} \]
\[ F_2 = \left( 8.99 \times 10^9 \right) \frac{{24 \times 10^{-12}}}{{(0.2)^2}} \]
\[ F_2 = \sab laug ( 8.99 \times 10^9 \right) \times 6 \times 10^{-11} \]
\[ F_2 = 0.5394 \, N \]
Yog li, thaum qhov deb ntawm ob qho nqi nce ntxiv los ntawm 0.1 m mus rau 0.2 m, lub zog Coulomb txo qis los ntawm 2.1576 N mus rau 0.5394 N.
Teeb Meem 3: Kev Ua Haujlwm ntawm Kev Tsiv Ib Lub Thauj Khoom
Ib qho nqi hluav taws xob \( q = 2 \, \mu C \) raug tsiv los ntawm qhov chaw A mus rau qhov chaw B hauv ib lub teb hluav taws xob nrog cov peev xwm \( V_A = 100 \, V \) thiab \( V_B = 40 \, V \). Muaj pes tsawg txoj haujlwm ua tiav los txav qhov nqi hluav taws xob?
Kev Sib Tham:
Cov haujlwm ua tiav los txav tus nqi hauv lub teb hluav taws xob tuaj yeem suav los ntawm kev siv cov mis:
\[ W = q (V_A – V_B) \]
Hloov cov nqi uas paub lawm:
– \( q = 2 \, \mu C = 2 \times 10^{-6} \, C \)
– \( V_A = 100 \, V \)
– \( V_B = 40 \, V \)
\[ W = (2 \times 10^{-6} \, C) (100 \, V – 40 \, V) \]
\[ W = (2 \times 10^{-6} \, C) \times 60 \, V \]
\[ W = 1.2 \times 10^{-4} \, J \]
Yog li, txoj haujlwm ua tiav los txav lub nqi yog \( 1.2 \times 10^{-4} \, J \).
Xaus
Hluav taws xob zoo li qub yog ib qho xwm txheej txaus nyiam uas feem ntau ua lub luag haujlwm hauv ntau yam xwm txheej txhua hnub. Kev nkag siab txog cov ntsiab lus yooj yim xws li Coulomb txoj cai thiab cov ntsiab cai ntawm cov teb hluav taws xob yog qhov tseem ceeb rau kev tshuaj xyuas thiab daws cov teeb meem cuam tshuam. Los ntawm cov piv txwv uas tau tham, peb tuaj yeem siv cov kev xav txog physics los nkag siab txog kev sib cuam tshuam ntawm cov nqi hluav taws xob thiab qhov loj ntawm cov zog ua haujlwm ntawm lawv. Nrog kev nkag siab zoo, peb tuaj yeem nkag siab zoo dua thiab tswj hwm qhov xwm txheej ntawm hluav taws xob zoo li qub hauv lub neej txhua hnub.
