added mass

src/draw/Particles.ts

@@ -7,11 +7,13 @@ const particles: Particle[] = [];
 
 
 export function particlesInit() {
+    const chargeToMass = [0.1, 1, 10];
     for (let i = 0; i < 200; i++) {
+        const charge = Math.random() < 0.3 ? 0 : Math.random() < 0.5 ? 1 : -1;
         particles.push(new Particle(new Vector(
             Math.random() * (CANVAS_WIDTH - 100) + 50,
             Math.random() * (CANVAS_HEIGHT - 100) + 50
-        ), Math.random() < 0.3 ? 0 : Math.random() < 0.6 ? -1 : 1));
+        ), charge, chargeToMass[charge - 1]));
     }
 }
 

src/draw/classes/Particle.ts

@@ -12,18 +12,18 @@ const RANDOM_ACCELERATION = 2;
 export default class Particle implements SimObject {
     private _position: Vector;
     private _velocity: Vector;
-    // private _color: FillStyle;
+    private _mass: number;
     private _charge: number;
 
-    constructor(position: Vector, /*color = "black", */charge = 0) {
+    constructor(position: Vector, charge = 0, mass = 1) {
         this._position = position;
         this._velocity = new Vector();
-        //this._color = color;
         this._charge = charge;
+        this._mass = mass;
     }
 
     public applyForce(force: Vector) {
-        this._velocity = this._velocity.add(force);
+        this._velocity = this._velocity.add(force.scaleInverse(this._mass));
     }
 
     public draw(ctx: Ctx): void {

src/draw/classes/Vector.ts

@@ -11,15 +11,19 @@ export default class Vector {
         return new Vector(this.x + b.x, this.y + b.y);
     }
 
-    public sub(b: Vector) {
+    public sub(b: Vector): Vector {
         return new Vector(this.x - b.x, this.y - b.y);
     }
 
-    public scale(number: number) {
-        return new Vector(this.x * number, this.y * number);
+    public scale(n: number): Vector {
+        return new Vector(this.x * n, this.y * n);
     }
 
-    public magnitude() {
+    public scaleInverse(n: number): Vector {
+        return new Vector(this.x / n, this.y / n);
+    }
+
+    public magnitude(): number {
         return Math.sqrt(this.x * this.x + this.y * this.y);
     }
 
@@ -27,12 +31,12 @@ export default class Vector {
         return Math.sqrt((this.x - b.x) ** 2 + (this.y - b.y) ** 2)
     }
 
-    public negated() {
+    public negated(): Vector {
         return new Vector(-this.x, -this.y);
     }
 
-    public normalized() {
+    public normalized(): Vector {
         const factor = this.magnitude();
         return new Vector(this.x / factor, this.y / factor);
     }
-}
+}