Mehlala ea Lipotso Tse Buisanang ka Motlakase o sa Fetoheng
Pendahuluan
Motlakase o sa fetoheng ke ketsahalo ea 'mele eo re atisang ho kopana le eona bophelong ba rona ba letsatsi le letsatsi. Ho tloha phihlelong ea ho tšoaroa ke motlakase o monyenyane ha re ama kotopo ea lemati ho isa phellong ea moriri o emeng ka lehlakoreng le leng ha re kama ka kama ea polasetiki, ntho e 'ngoe le e 'ngoe e ka hlalosoa ka melao-motheo ea motlakase o sa fetoheng. Sehlooho sena se tla tšohla mehlala e 'maloa ea mathata a motlakase o sa fetoheng, se totobatse likhopolo tsa motheo le ho sebelisa melao e sebetsang.
Ho Utloisisa Motlakase o sa Fetoheng
Motlakase o sa fetoheng ke ho bokellana ha tjhaja ya motlakase hodima ntho. Sena se etsahala ka lebaka la phetiso ya dielektrone ho tloha nthong e nngwe ho ya ho e nngwe, hangata e bakwang ke kgohlano, jwalo ka ha balune e hohlana le moriri. Matla a hlahang ho tjhaja ena ya motlakase a laolwa ke molao wa Coulomb.
Molao oa Coulomb o bolela hore matla a pakeng tsa lintho tse peli tse tjhajwang a lekana le sehlahisoa sa boholo ba litefiso tse amehang 'me a lekana ka tsela e fapaneng le sekwere sa sebaka se pakeng tsa tsona. Foromo ea lipalo bakeng sa molao ona ke:
\[ F = k \frac{{|q_1 q_2|}}{{r^2}} \]
Moo:
– \( F \) ke matla a pakeng tsa liqoso tse peli,
– \( k \) ke constant ya Coulomb (\( 8.99 \times 10^9 \, N \cdot m^2 / C^2 \)),
– \( q_1 \) le \( q_2 \) ke boholo ba tjhaja ya motlakase, mme
– \( r \) ke sebaka se pakeng tsa litefiso tse peli.
Lipotso le Lipuisano tsa Mehlala
Potso ea 1: Ho Bala Matla a Motlakase a Coulomb
Litefiso tse peli tsa boholo ba \( 5 \, \mu C \) le \( -3 \, \mu C \) li behiloe sebakeng sa 20 cm. Bala matla a motlakase pakeng tsa litefiso tse peli!
Puisano:
Taba ea pele, fetola li-unit tsa tjhaja le sebaka hore e be tsamaiso ea machaba (SI):
– \( q_1 = 5 \, \mu C = 5 \makgetlo a 10^{-6} \, C \)
– \( q_2 = -3 \, \mu C = -3 \makgetlo a 10^{-6} \, C \)
– \( r = 20 \, cm = 0.2 \, m \)
Sebelisa molao oa Coulomb ho bala matla:
\[ F = k \frac{{|q_1 q_2|}}{{r^2}} \]
Kenya mekhoa e tsebahalang sebakeng sa eona:
\[ F = \left( 8.99 \times 10^9 \frac{N \cdot m^2}{C^2} \right) \frac{{|5 \times 10^{-6} \, C \times (-3 \times 10^{-6} \, C)|}}{{(0.2 \, m)^2}} \]
\[ F = \left( 8.99 \times 10^9 \right) \frac{{15 \times 10^{-12}}}{{0.04}} \]
\[ F = \left( 8.99 \makgetlo a 10^9 \leright) \makgetlo a 3.75 \makgetlo a 10^{-10} \]
\[ F = 3.37 \, N \]
Matla a pakeng tsa liqoso tse peli ke 3.37 N 'me kaha e' ngoe ea liqoso ke e mpe, matla ana aa hohela.
Potso ea 2: Tšusumetso ea Sebaka Matla a Coulomb
Litefiso tse peli \( +4 \, \mu C \) le \( +6 \, \mu C \) li behiloe bohōle ba 0.1 m. Haeba sebaka se pakeng tsa litefiso tse peli se eketsoa ho fihlela ho 0.2 m, fumana hore na matla a Coulomb a fetoha joang!
Puisano:
Taba ea pele, bala matla a sebaka sa pele \( 0.1\, m \):
– \( q_1 = 4 \, \mu C = 4 \makgetlo a 10^{-6} \, C \)
– \( q_2 = 6 \, \mu C = 6 \makgetlo a 10^{-6} \, C \)
– \( r_1 = 0.1 \, m \)
\[ F_1 = k \frac{{|q_1 q_2|}}{{r_1^2}} \]
Kenya mekhoa e tsebahalang sebakeng sa eona:
\[ F_1 = \left( 8.99 \times 10^9 \right) \frac{{24 \times 10^{-12}}}{{(0.1)^2}} \]
\[ F_1 = \ka ho le letshehadi( 8.99 \ka makhetlo a 10^9 \ka ho le letona) \ka makhetlo a 2.4 \ka makhetlo a 10^{-10} \]
\[ F_1 = 2.1576 \, N \]
Jwale, bala matla sebakeng se setjha \( 0.2 \, m \):
– \( r_2 = 0.2 \, m \)
\[ F_2 = k \frac{{|q_1 q_2|}}{{r_2^2}} \]
\[ F_2 = \left( 8.99 \times 10^9 \right) \frac{{24 \times 10^{-12}}}{{(0.2)^2}} \]
\[ F_2 = \ka ho le letshehadi( 8.99 \ka makhetlo a 10^9 \ka ho le letona) \ka makhetlo a 6 \ka makhetlo a 10^{-11} \]
\[ F_2 = 0.5394 \, N \]
Kahoo, ha sebaka se pakeng tsa litefiso tse peli se eketseha ho tloha ho 0.1 m ho isa ho 0.2 m, matla a Coulomb a fokotseha ho tloha ho 2.1576 N ho isa ho 0.5394 N.
Bothata ba 3: Mosebetsi oa ho Jara Mojaro
Tefiso \( q = 2 \, \mu C \) e fetisoa ho tloha ntlheng ea A ho ea ntlheng ea B tšimong ea motlakase e nang le matla \( V_A = 100 \, V \) le \( V_B = 40 \, V \). Ke mosebetsi o mokae o etsoang ho tsamaisa tefiso?
Puisano:
Mosebetsi o etsoang ho tsamaisa tjhaja tšimong ea motlakase o ka baloa ho sebelisoa foromo:
\[ W = q (V_A – V_B) \]
Kenya mekhoa e tsebahalang sebakeng sa eona:
– \( q = 2 \, \mu C = 2 \makgetlo a 10^{-6} \, C \)
– \( V_A = 100 \, V \)
– \( V_B = 40 \, V \)
\[ W = (2 \makgetlo a 10^{-6} \, C) (100 \, V – 40 \, V) \]
\[ W = (2 \makgetlo a 10^{-6} \, C) \makgetlo a 60 \, V \]
\[ W = 1.2 \makgetlo a 10^{-4} \, J \]
Kahoo, mosebetsi o etsoang ho tsamaisa tjhaja ke \( 1.2 \times 10^{-4} \, J \).
Qetello
Motlakase o sa fetoheng ke ketsahalo e khahlang eo hangata e bapalang karolo maemong a fapaneng a letsatsi le letsatsi. Ho utloisisa mehopolo ea mantlha joalo ka molao oa Coulomb le melao-motheo ea masimo a motlakase ho bohlokoa bakeng sa ho sekaseka le ho rarolla mathata a amanang. Ka mehlala e tšohliloeng, re ka sebelisa likhopolo-taba tsa fisiks ho utloisisa likamano lipakeng tsa litefiso tsa motlakase le boholo ba matla a sebetsang lipakeng tsa tsona. Ka kutloisiso e tiileng, re ka ananela le ho laola ketsahalo ea motlakase o sa fetoheng hamolemo bophelong ba letsatsi le letsatsi.
