{"id":2340,"date":"2025-05-23T21:09:37","date_gmt":"2025-05-23T18:09:37","guid":{"rendered":"https:\/\/cedra.academy\/?p=2340"},"modified":"2025-09-09T21:19:01","modified_gmt":"2025-09-09T18:19:01","slug":"sarcina-electrica-legea-conservarii-sarcinii-electrice-legea-lui-coulomb","status":"publish","type":"post","link":"https:\/\/cedra.academy\/?p=2340","title":{"rendered":"Sarcina electric\u0103. Legea conserv\u0103rii sarcinii electrice. Legea lui Coulomb"},"content":{"rendered":"\n
Sarcina electric\u0103. Legea conserv\u0103rii sarcinii electrice. Legea lui Coulomb PPTX .<\/a>Descarc\u0103<\/a><\/div>\n\n\n\n

<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Sarcina electric\u0103 este o proprietate fundamental\u0103 a particulelor subatomice care determin\u0103 interac\u021biunea lor electric\u0103. Cele mai cunoscute particule \u00eenc\u0103rcate sunt electronii<\/strong>, care au sarcin\u0103 negativ\u0103, \u0219i protonii<\/strong>, care au sarcin\u0103 pozitiv\u0103.<\/p>\n\n\n\n

Exist\u0103 dou\u0103 tipuri de sarcin\u0103 electric\u0103:<\/p>\n\n\n\n

    \n
  • Sarcin\u0103 pozitiv\u0103 (+)<\/strong> \u2013 asociat\u0103 protonilor.<\/li>\n\n\n\n
  • Sarcin\u0103 negativ\u0103 (\u2212)<\/strong> \u2013 asociat\u0103 electronilor.<\/li>\n<\/ul>\n\n\n\n

    Principalele caracteristici ale sarcinii electrice sunt:<\/p>\n\n\n\n

      \n
    1. Discre\u021bia:<\/strong> sarcina electric\u0103 apare \u00eentotdeauna sub form\u0103 de multipli ai unei sarcini fundamentale e=1,6\u22c510\u221219\u2009Ce = 1,6 \\cdot 10^{-19} \\, \\text{C}e=1,6\u22c510\u221219C (Coulomb).<\/li>\n\n\n\n
    2. Conservarea:<\/strong> sarcina nu poate fi creat\u0103 sau distrus\u0103 prin procese obi\u0219nuite, ci doar transferat\u0103 de la un corp la altul.<\/li>\n\n\n\n
    3. Interac\u021biunea:<\/strong> sarcinile de acela\u0219i semn se resping, iar sarcinile de semn opus se atrag.<\/li>\n<\/ol>\n\n\n\n

      Sarcina electric\u0103 se m\u0103soar\u0103 \u00een Coulombi (C)<\/strong>. De exemplu, un electron are sarcina qe=\u22121,6\u22c510\u221219\u2009Cq_e = -1,6 \\cdot 10^{-19} \\, \\text{C}qe\u200b=\u22121,6\u22c510\u221219C, iar un proton qp=+1,6\u22c510\u221219\u2009Cq_p = +1,6 \\cdot 10^{-19} \\, \\text{C}qp\u200b=+1,6\u22c510\u221219C.<\/p>\n\n\n\n

      Legea conserv\u0103rii sarcinii electrice<\/strong><\/h2>\n\n\n\n

      Legea conserv\u0103rii sarcinii electrice afirm\u0103 c\u0103 \u00een orice proces fizic sau chimic, sarcina electric\u0103 total\u0103 se p\u0103streaz\u0103 constant\u0103<\/strong>.<\/p>\n\n\n\n

      Aceasta \u00eenseamn\u0103 c\u0103:<\/p>\n\n\n\n

        \n
      • Dac\u0103 un obiect pierde sarcin\u0103, aceasta apare exact pe alt obiect.<\/li>\n\n\n\n
      • Nu se poate crea sau distruge sarcin\u0103 \u201cdin nimic\u201d.<\/li>\n<\/ul>\n\n\n\n

        Exemplu:<\/strong><\/p>\n\n\n\n

          \n
        • \u00centr-un experiment de frecare, un baghet de plastic devine \u00eenc\u0103rcat\u0103 negativ prin preluarea electronilor de pe o bucat\u0103 de p\u00e2nz\u0103. P\u00e2nza r\u0103m\u00e2ne \u00eenc\u0103rcat\u0103 pozitiv cu aceea\u0219i cantitate de sarcin\u0103, deci sarcina total\u0103 a sistemului se p\u0103streaz\u0103.<\/li>\n<\/ul>\n\n\n\n

          Aceast\u0103 lege st\u0103 la baza tuturor fenomenelor electrice \u0219i este extrem de important\u0103 \u00een tehnologie \u0219i \u00een natur\u0103.<\/p>\n\n\n\n

          Legea lui Coulomb<\/strong><\/h2>\n\n\n\n

          Legea lui Coulomb descrie for\u021ba electric\u0103<\/strong> dintre dou\u0103 corpuri \u00eenc\u0103rcate punctual. Aceasta a fost formulat\u0103 \u00een secolul XVIII de fizicianul francez Charles-Augustin de Coulomb<\/strong>.<\/p>\n\n\n\n

          Enun\u021bul legii:<\/strong><\/p>\n\n\n\n

          \n

          For\u021ba de atrac\u021bie sau respingere dintre dou\u0103 sarcini punctuale este direct propor\u021bional\u0103 cu produsul valorilor sarcinilor \u0219i invers propor\u021bional\u0103 cu p\u0103tratul distan\u021bei dintre ele.<\/p>\n<\/blockquote>\n\n\n\n

          Matematic, legea lui Coulomb se scrie astfel: F=k\u22c5\u2223q1\u22c5q2\u2223r2F = k \\cdot \\frac{|q_1 \\cdot q_2|}{r^2}F=k\u22c5r2\u2223q1\u200b\u22c5q2\u200b\u2223\u200b<\/p>\n\n\n\n

          unde:<\/p>\n\n\n\n

            \n
          • FFF \u2013 for\u021ba electric\u0103 dintre sarcini (\u00een newtoni, N)<\/li>\n\n\n\n
          • q1,q2q_1, q_2q1\u200b,q2\u200b \u2013 valorile sarcinilor (\u00een coulombi, C)<\/li>\n\n\n\n
          • rrr \u2013 distan\u021ba dintre sarcini (\u00een metri, m)<\/li>\n\n\n\n
          • kkk \u2013 constanta electrostatic\u0103 k\u22489\u22c5109\u2009N\\cdotpm\u00b2\/C\u00b2k \\approx 9 \\cdot 10^9 \\, \\text{N\u00b7m\u00b2\/C\u00b2}k\u22489\u22c5109N\\cdotpm\u00b2\/C\u00b2<\/li>\n<\/ul>\n\n\n\n

            Propriet\u0103\u021bi importante:<\/strong><\/p>\n\n\n\n

              \n
            1. For\u021ba este atractiv\u0103<\/strong> dac\u0103 sarcinile au semne opuse \u0219i repulsiv\u0103<\/strong> dac\u0103 sarcinile au acela\u0219i semn.<\/li>\n\n\n\n
            2. Direc\u021bia for\u021bei este de-a lungul liniei care une\u0219te cele dou\u0103 sarcini.<\/li>\n\n\n\n
            3. For\u021ba este un vector<\/strong>, ceea ce \u00eenseamn\u0103 c\u0103 are at\u00e2t m\u0103rime, c\u00e2t \u0219i direc\u021bie.<\/li>\n<\/ol>\n\n\n\n

              Exemplu practic:<\/strong>
              Dac\u0103 dou\u0103 particule cu sarcina q1=2\u2009\u03bcCq_1 = 2 \\, \\mu Cq1\u200b=2\u03bcC \u0219i q2=\u22123\u2009\u03bcCq_2 = -3 \\, \\mu Cq2\u200b=\u22123\u03bcC se afl\u0103 la distan\u021ba de 0,5 m una de cealalt\u0103, for\u021ba electric\u0103 dintre ele poate fi calculat\u0103 cu legea lui Coulomb. Sarcinile fiind de semn opus, se vor atrage.<\/p>\n\n\n\n

              Rezumat<\/strong><\/h3>\n\n\n\n
                \n
              1. Sarcina electric\u0103 poate fi pozitiv\u0103 sau negativ\u0103 \u0219i este proprietatea care determin\u0103 interac\u021biunile electrice.<\/li>\n\n\n\n
              2. Legea conserv\u0103rii sarcinii afirm\u0103 c\u0103 sarcina total\u0103 a unui sistem izolat r\u0103m\u00e2ne constant\u0103.<\/li>\n\n\n\n
              3. Legea lui Coulomb permite calcularea for\u021bei electrice dintre dou\u0103 sarcini \u0219i explic\u0103 atrac\u021bia sau respingerea lor.<\/li>\n<\/ol>\n\n\n\n
                \"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

                Sarcina electric\u0103 este o proprietate fundamental\u0103 a particulelor subatomice care determin\u0103 interac\u021biunea lor electric\u0103. Cele mai cunoscute particule \u00eenc\u0103rcate sunt electronii, care au sarcin\u0103 negativ\u0103, \u0219i protonii, care au sarcin\u0103 […]<\/p>\n","protected":false},"author":1,"featured_media":2341,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[18,10],"tags":[],"_links":{"self":[{"href":"https:\/\/cedra.academy\/index.php?rest_route=\/wp\/v2\/posts\/2340"}],"collection":[{"href":"https:\/\/cedra.academy\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cedra.academy\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cedra.academy\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/cedra.academy\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2340"}],"version-history":[{"count":1,"href":"https:\/\/cedra.academy\/index.php?rest_route=\/wp\/v2\/posts\/2340\/revisions"}],"predecessor-version":[{"id":2345,"href":"https:\/\/cedra.academy\/index.php?rest_route=\/wp\/v2\/posts\/2340\/revisions\/2345"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cedra.academy\/index.php?rest_route=\/wp\/v2\/media\/2341"}],"wp:attachment":[{"href":"https:\/\/cedra.academy\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2340"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cedra.academy\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2340"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cedra.academy\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2340"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}