{"id":2458,"date":"2026-02-13T23:03:30","date_gmt":"2026-02-13T21:03:30","guid":{"rendered":"https:\/\/science-x.net\/?page_id=2458"},"modified":"2026-02-13T23:03:31","modified_gmt":"2026-02-13T21:03:31","slug":"coulombs-law-calculator","status":"publish","type":"page","link":"https:\/\/science-x.net\/?page_id=2458","title":{"rendered":"Coulomb\u2019s Law Calculator"},"content":{"rendered":"\n<div class=\"eco-tool wp-block-group\" id=\"eco-tool-coulomb-5b71e\">\n  <div class=\"eco-tool__header\">\n    <h2 class=\"eco-tool__title\">Coulomb\u2019s Law Calculator<\/h2>\n    <p class=\"eco-tool__lead\">\n      Calculate electrostatic force between two point charges: F = k\u00b7|q\u2081q\u2082|\/r\u00b2 (in vacuum\/air, approx.).\n    <\/p>\n  <\/div>\n\n  <form class=\"eco-tool__form\" id=\"eco-coul-form-5b71e\" novalidate>\n    <div class=\"eco-tool__grid3\">\n      <!-- k -->\n      <div class=\"eco-tool__field\">\n        <label class=\"eco-tool__label\" for=\"eco-coul-k-5b71e\">\n          Coulomb constant (k)<br>(N\u00b7m\u00b2\/C\u00b2)\n        <\/label>\n        <input class=\"eco-tool__input\" id=\"eco-coul-k-5b71e\" type=\"number\" step=\"any\" value=\"8.9875517923e9\" inputmode=\"decimal\" \/>\n        <div class=\"eco-tool__hint\">Default \u2248 8.99\u00d710\u2079 (vacuum\/air).<\/div>\n      <\/div>\n\n      <!-- q1 -->\n      <div class=\"eco-tool__field\">\n        <label class=\"eco-tool__label\" for=\"eco-coul-q1-5b71e\">\n          Charge 1 (q\u2081)<br>(Coulombs, C)\n        <\/label>\n        <input class=\"eco-tool__input\" id=\"eco-coul-q1-5b71e\" type=\"number\" step=\"any\" placeholder=\"e.g., 2e-6\" inputmode=\"decimal\" \/>\n        <div class=\"eco-tool__hint\">Can be negative (e.g., -1e-6).<\/div>\n      <\/div>\n\n      <!-- q2 -->\n      <div class=\"eco-tool__field\">\n        <label class=\"eco-tool__label\" for=\"eco-coul-q2-5b71e\">\n          Charge 2 (q\u2082)<br>(Coulombs, C)\n        <\/label>\n        <input class=\"eco-tool__input\" id=\"eco-coul-q2-5b71e\" type=\"number\" step=\"any\" placeholder=\"e.g., -3e-6\" inputmode=\"decimal\" \/>\n        <div class=\"eco-tool__hint\">Use scientific notation if needed (1e-6).<\/div>\n      <\/div>\n\n      <!-- r -->\n      <div class=\"eco-tool__field\">\n        <label class=\"eco-tool__label\" for=\"eco-coul-r-5b71e\">\n          Separation distance (r)<br>(meters)\n        <\/label>\n        <input class=\"eco-tool__input\" id=\"eco-coul-r-5b71e\" type=\"number\" min=\"0\" step=\"any\" placeholder=\"e.g., 0.05\" inputmode=\"decimal\" \/>\n        <div class=\"eco-tool__hint\">Center-to-center distance (r &gt; 0).<\/div>\n      <\/div>\n\n      <!-- Formula -->\n      <div class=\"eco-tool__field\">\n        <label class=\"eco-tool__label\">Formulas<\/label>\n        <div class=\"eco-tool__noteBox\">\n          Magnitude: F = k\u00b7|q\u2081q\u2082| \/ r\u00b2<br>\n          Field from q\u2081: E = k\u00b7q\u2081 \/ r\u00b2<br>\n          Force on q\u2082: F = q\u2082\u00b7E\n        <\/div>\n        <div class=\"eco-tool__hint\">Assumes point charges and vacuum\/air.<\/div>\n      <\/div>\n\n      <!-- Tip -->\n      <div class=\"eco-tool__field\">\n        <label class=\"eco-tool__label\">Tip<\/label>\n        <div class=\"eco-tool__noteBox\">\n          Same signs repel, opposite signs attract. Force grows quickly as distance decreases (1\/r\u00b2).\n        <\/div>\n        <div class=\"eco-tool__hint\">Real materials can reduce force (dielectric).<\/div>\n      <\/div>\n    <\/div>\n\n    <div class=\"eco-tool__actions\">\n      <button type=\"button\" class=\"wp-element-button eco-tool__btn\" id=\"eco-coul-calc-5b71e\">Calculate<\/button>\n      <button type=\"button\" class=\"wp-element-button eco-tool__btn eco-tool__btn--ghost\" id=\"eco-coul-reset-5b71e\">Reset<\/button>\n      <div class=\"eco-tool__error\" id=\"eco-coul-error-5b71e\" aria-live=\"polite\"><\/div>\n    <\/div>\n  <\/form>\n\n  <div class=\"eco-tool__result\" id=\"eco-coul-result-5b71e\" hidden>\n    <h3 class=\"eco-tool__subtitle\">Results<\/h3>\n\n    <div class=\"eco-tool__cards\">\n      <div class=\"eco-tool__card\">\n        <div class=\"eco-tool__metric-label\">Force magnitude (|F|)<\/div>\n        <div class=\"eco-tool__metric-value\" id=\"eco-coul-out-f-5b71e\">\u2014<\/div>\n        <div class=\"eco-tool__metric-sub\">Newtons (N)<\/div>\n      <\/div>\n\n      <div class=\"eco-tool__card\">\n        <div class=\"eco-tool__metric-label\">Interaction<\/div>\n        <div class=\"eco-tool__metric-value\" id=\"eco-coul-out-type-5b71e\">\u2014<\/div>\n        <div class=\"eco-tool__metric-sub\">Based on charge signs<\/div>\n      <\/div>\n\n      <div class=\"eco-tool__card\">\n        <div class=\"eco-tool__metric-label\">Electric field from q\u2081 at q\u2082<\/div>\n        <div class=\"eco-tool__metric-value\" id=\"eco-coul-out-e-5b71e\">\u2014<\/div>\n        <div class=\"eco-tool__metric-sub\">N\/C (or V\/m)<\/div>\n      <\/div>\n    <\/div>\n\n    <div class=\"eco-tool__card eco-tool__card--wide\">\n      <div class=\"eco-tool__metric-label\">Equation<\/div>\n      <div class=\"eco-tool__metric-sub\" id=\"eco-coul-eq-5b71e\">\u2014<\/div>\n      <div class=\"eco-tool__metric-sub eco-tool__muted\">Supports scientific notation (e.g., 2e-6).<\/div>\n    <\/div>\n\n    <p class=\"eco-tool__note\">\n      This is an ideal model. In materials, the effective force is reduced by the dielectric constant.\n    <\/p>\n  <\/div>\n<\/div>\n\n<style>\n.eco-tool{border:1px solid rgba(0,0,0,.12);border-radius:12px;padding:16px}\n.eco-tool__grid3{display:grid;grid-template-columns:1fr;gap:16px}\n@media (min-width:860px){.eco-tool__grid3{grid-template-columns:1fr 1fr 1fr}}\n.eco-tool__field{display:flex;flex-direction:column;gap:6px}\n.eco-tool__label{font-weight:600}\n.eco-tool__input{height:44px;padding:0 12px;border:1px solid rgba(0,0,0,.2);border-radius:10px;background:#fff;font:inherit;box-sizing:border-box}\n.eco-tool__hint{font-size:.92em;opacity:.78;min-height:38px}\n.eco-tool__noteBox{border:1px solid rgba(0,0,0,.12);border-radius:12px;padding:12px;background:rgba(0,0,0,.02);min-height:44px}\n\n.eco-tool__actions{display:flex;gap:10px;margin-top:16px;align-items:center;flex-wrap:wrap}\n.eco-tool__btn{padding:10px 22px}\n.eco-tool__btn--ghost{background:transparent!important;border:1px solid rgba(0,0,0,.2)!important}\n.eco-tool__btn--ghost:hover,.eco-tool__btn--ghost:focus{background:rgba(0,0,0,.06)!important;border-color:rgba(0,0,0,.35)!important}\n.eco-tool__error{font-weight:600;min-height:1.2em;flex:1 1 240px}\n\n.eco-tool__result{margin-top:16px}\n.eco-tool__subtitle{margin:0 0 10px}\n.eco-tool__cards{display:grid;gap:10px;grid-template-columns:1fr}\n@media (min-width:860px){.eco-tool__cards{grid-template-columns:1fr 1fr 1fr}}\n.eco-tool__card{border:1px solid rgba(0,0,0,.12);border-radius:12px;padding:12px}\n.eco-tool__card--wide{margin-top:10px}\n.eco-tool__metric-label{opacity:.85;font-weight:600}\n.eco-tool__metric-value{font-size:1.6em;font-weight:800;margin-top:6px;line-height:1.1}\n.eco-tool__metric-sub{opacity:.85;margin-top:6px}\n.eco-tool__muted{opacity:.8}\n.eco-tool__note{margin-top:10px;opacity:.9}\n<\/style>\n\n<script>\n(function(){\n  const S=\"5b71e\";\n  const el=(id)=>document.getElementById(id+\"-\"+S);\n\n  const kEl=el(\"eco-coul-k\");\n  const q1El=el(\"eco-coul-q1\");\n  const q2El=el(\"eco-coul-q2\");\n  const rEl=el(\"eco-coul-r\");\n\n  const calcBtn=el(\"eco-coul-calc\");\n  const resetBtn=el(\"eco-coul-reset\");\n  const errEl=el(\"eco-coul-error\");\n\n  const resEl=el(\"eco-coul-result\");\n  const outF=el(\"eco-coul-out-f\");\n  const outType=el(\"eco-coul-out-type\");\n  const outE=el(\"eco-coul-out-e\");\n  const eqEl=el(\"eco-coul-eq\");\n\n  function setError(msg){ errEl.textContent = msg || \"\"; }\n  function fmt(n,d){\n    if(!Number.isFinite(n)) return \"\u2014\";\n    const a=Math.abs(n);\n    if(a===0) return \"0\";\n    if(a<0.001 || a>=1e9) return n.toExponential(3);\n    return n.toLocaleString(undefined,{maximumFractionDigits:d});\n  }\n\n  function calculate(){\n    setError(\"\");\n\n    const k = Number(kEl.value);\n    const q1 = Number(q1El.value);\n    const q2 = Number(q2El.value);\n    const r = Number(rEl.value);\n\n    if(!Number.isFinite(k) || k <= 0){\n      setError(\"Enter a valid Coulomb constant (k).\");\n      resEl.hidden = true; return;\n    }\n    if(!Number.isFinite(q1) || !Number.isFinite(q2)){\n      setError(\"Enter valid charges q\u2081 and q\u2082 (C).\");\n      resEl.hidden = true; return;\n    }\n    if(!Number.isFinite(r) || r <= 0){\n      setError(\"Enter a valid distance r (meters).\");\n      resEl.hidden = true; return;\n    }\n\n    const Fmag = (k * Math.abs(q1*q2)) \/ (r*r);\n    const E = (k * q1) \/ (r*r); \/\/ signed field from q1 at the point\n    const type = (q1 === 0 || q2 === 0) ? \"No force (one charge is 0)\" : ((q1*q2) > 0 ? \"Repulsion\" : \"Attraction\");\n\n    outF.textContent = `${fmt(Fmag,6)} N`;\n    outType.textContent = type;\n    outE.textContent = `${fmt(E,6)} N\/C`;\n\n    eqEl.textContent = `|F| = k\u00b7|q\u2081q\u2082|\/r\u00b2 = ${fmt(k,6)}\u00b7|${fmt(q1,6)}\u00d7${fmt(q2,6)}|\/${fmt(r,6)}\u00b2`;\n\n    resEl.hidden = false;\n  }\n\n  function reset(){\n    kEl.value = \"8.9875517923e9\";\n    q1El.value = \"\";\n    q2El.value = \"\";\n    rEl.value = \"\";\n    setError(\"\");\n    resEl.hidden = true;\n  }\n\n  calcBtn.addEventListener(\"click\", calculate);\n  resetBtn.addEventListener(\"click\", reset);\n})();\n<\/script>\n\n","protected":false},"excerpt":{"rendered":"<p>Coulomb\u2019s Law Calculator Calculate electrostatic force between two point charges: F = k\u00b7|q\u2081q\u2082|\/r\u00b2 (in vacuum\/air, approx.). Coulomb constant (k)(N\u00b7m\u00b2\/C\u00b2) Default \u2248 8.99\u00d710\u2079 (vacuum\/air). Charge 1 (q\u2081)(Coulombs, C) Can be negative&hellip;<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":2354,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_sitemap_exclude":false,"_sitemap_priority":"","_sitemap_frequency":"","footnotes":""},"_links":{"self":[{"href":"https:\/\/science-x.net\/index.php?rest_route=\/wp\/v2\/pages\/2458"}],"collection":[{"href":"https:\/\/science-x.net\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/science-x.net\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/science-x.net\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/science-x.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2458"}],"version-history":[{"count":1,"href":"https:\/\/science-x.net\/index.php?rest_route=\/wp\/v2\/pages\/2458\/revisions"}],"predecessor-version":[{"id":2459,"href":"https:\/\/science-x.net\/index.php?rest_route=\/wp\/v2\/pages\/2458\/revisions\/2459"}],"up":[{"embeddable":true,"href":"https:\/\/science-x.net\/index.php?rest_route=\/wp\/v2\/pages\/2354"}],"wp:attachment":[{"href":"https:\/\/science-x.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2458"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}