[FEAT] Add Coulomb's Law for electrostatics (#7017)

Co-authored-by: Priyanshu1303d <priyanshu130d@gmail.com>

src/main/java/com/thealgorithms/maths/JugglerSequence.java

@@ -43,7 +43,7 @@ public final class JugglerSequence {
             seq.add(n + "");
         }
         String res = String.join(",", seq);
-        System.out.println(res);
+        System.out.print(res + "\n");
     }
 
     // Driver code

src/main/java/com/thealgorithms/physics/CoulombsLaw.java

@@ -0,0 +1,80 @@
+package com.thealgorithms.physics;
+
+/**
+ * Implements Coulomb's Law for electrostatics.
+ * Provides simple static methods to calculate electrostatic force and circular orbit velocity.
+ *
+ * @author [Priyanshu Singh](https://github.com/Priyanshu1303d)
+ * @see <a href="https://en.wikipedia.org/wiki/Coulomb%27s_law">Wikipedia</a>
+ */
+public final class CoulombsLaw {
+
+    /** Coulomb's constant in N·m²/C² */
+    public static final double COULOMBS_CONSTANT = 8.9875517923e9;
+
+    /**
+     * Private constructor to prevent instantiation of this utility class.
+     */
+    private CoulombsLaw() {
+    }
+
+    /**
+     * Calculates the electrostatic force vector exerted by one charge on another.
+     * The returned vector is the force *on* the second charge (q2).
+     *
+     * @param q1 Charge of the first particle (in Coulombs).
+     * @param x1 X-position of the first particle (m).
+     * @param y1 Y-position of the first particle (m).
+     * @param q2 Charge of the second particle (in Coulombs).
+     * @param x2 X-position of the second particle (m).
+     * @param y2 Y-position of the second particle (m).
+     * @return A double array `[fx, fy]` representing the force vector on the second charge.
+     */
+    public static double[] calculateForceVector(double q1, double x1, double y1, double q2, double x2, double y2) {
+        // Vector from 1 to 2
+        double dx = x2 - x1;
+        double dy = y2 - y1;
+        double distanceSq = dx * dx + dy * dy;
+
+        // If particles are at the same position, force is zero to avoid division by zero.
+        if (distanceSq == 0) {
+            return new double[] {0, 0};
+        }
+
+        double distance = Math.sqrt(distanceSq);
+        // Force magnitude: k * (q1 * q2) / r^2
+        // A positive result is repulsive (pushes q2 away from q1).
+        // A negative result is attractive (pulls q2 toward q1).
+        double forceMagnitude = COULOMBS_CONSTANT * q1 * q2 / distanceSq;
+
+        // Calculate the components of the force vector
+        // (dx / distance) is the unit vector pointing from 1 to 2.
+        double fx = forceMagnitude * (dx / distance);
+        double fy = forceMagnitude * (dy / distance);
+
+        return new double[] {fx, fy};
+    }
+
+    /**
+     * Calculates the speed required for a stable circular orbit of a charged particle
+     * around a central charge (e.g., an electron orbiting a nucleus).
+     *
+     * @param centralCharge The charge of the central body (in Coulombs).
+     * @param orbitingCharge The charge of the orbiting body (in Coulombs).
+     * @param orbitingMass The mass of the orbiting body (in kg).
+     * @param radius The radius of the orbit (in m).
+     * @return The orbital speed (in m/s).
+     * @throws IllegalArgumentException if mass or radius are not positive.
+     */
+    public static double calculateCircularOrbitVelocity(double centralCharge, double orbitingCharge, double orbitingMass, double radius) {
+        if (orbitingMass <= 0 || radius <= 0) {
+            throw new IllegalArgumentException("Orbiting mass and radius must be positive.");
+        }
+
+        // We only need the magnitude of the force, which is always positive.
+        double forceMagnitude = Math.abs(COULOMBS_CONSTANT * centralCharge * orbitingCharge) / (radius * radius);
+
+        // F_c = m * v^2 / r  =>  v = sqrt(F_c * r / m)
+        return Math.sqrt(forceMagnitude * radius / orbitingMass);
+    }
+}