I am currently on spring break and since I only work 25 hours a week I have too much free time on my hands. I am a Computer Science student and I decided to spend my free time improving my coding skills and my understanding of electromagnetic physics by creating a very simple calculator that is used to solve Coulomb's law with vectors which are used to solve the force between any two charged particles in a system of charged particles.
Now I have a somewhat accurate calculator working, I still have a few minor inaccuracies that I need to address but the code can be found down below, but it still works enough for the next step I would like to achieve.
This next step for me is to create a GUI and an interactive graph for the users to see. I say interactive because my ideal program would give the user the ability to drag and drop points on the canvas all the while the program is calculating the force vectors and net force that is present between the points the user places on the space. I would also be satisfied with just being able to draw the graph given the charges and XY-coordinates as well.
My question is does anyone know of any good tutorials or respectable libraries that I can look into to achieve either of these two ideas? I have a strong background in Java so I would prefer this to be done in Java, but I am never one to step away from learning a new language when I need too.
Code:
Charge.java
package objects;
/**
* Charge is an object used to represent an arbitrarily charged particle in some
* XY-plane. This class will store the value of the charge, the XY-coordinates
* of that charge's location, and functions to access these values.
*
* @author Seth
*
*/
public class Charge {
private double q; // the charge of the particle in Coulombs
private double x; // the location along the x-axis of the charge
private double y; // the location along the y-axis of the charge
public Charge(double x, double y, double q) {
this.x = x;
this.y = y;
this.q = q;
}
/**
* public method to get q
*
* @return
* double - value of the Charge object
*/
public double getQ() {
if (this != null)
return q;
else
return 0;
}
/**
* public method to get x
*
* @return
* double - value of the x coordinate
*/
public double getX() {
if (this != null)
return x;
else
return 0;
}
/**
* public method to get y
*
* @return
* double - value of the y coordinate
*/
public double getY() {
if (this != null)
return y;
else
return 0;
}
}
ElectricForceCalculator.java
package objects;
/**
* ElectricForceCalculator is a class that has the ability to solve the net
* force between two charged particles in a xy-plane
*
* @author Seth
*
*/
public class ElectricForceCalculator {
/**
* Private method used to find the force between two charges
*
* @param Q
* Charge - The charged we are focused on
* @param q
* Charge - The second charge effecting Q
* @return double array - the force vectors found where i = 0 is the x
* direction and i = 1 is the y direction
*/
private double[] calcForceHelper(Charge Q, Charge q) {
double radius, quanOfCharge;
double[] radiusVector = new double[2], forceVector = new double[2];
double x1 = Q.getX(), y1 = Q.getY();
double x2 = q.getX(), y2 = q.getY();
double q1 = Q.getQ(), q2 = q.getQ();
System.out.print("Calculating radius of Q and q...\n\t");
radius = calcRadius(x1, x2, y1, y2);
System.out.print("Calculating radiusVector of Q and q...\n\t");
radiusVector = calcRadiusVector(x1, x2, y1, y2, radius);
System.out.print("Calculating quantityOfCharge of Q and q...\n\t");
quanOfCharge = calcCharge(q1, q2, radius);
System.out.print("Calculating Force Vector of Q and q...\n\t");
forceVector = calcForceVector(radius, radiusVector, quanOfCharge);
return forceVector;
}
/**
* Public method used to find the overall net force of a system of charged
* particles
*
* @param Q
* Charge - the Charge object we are focused on
* @param q
* Charge array - the list of all the other Charge object
* effecting Q
* @param numCharges
* int - the number of indices found in the list of Charge
* objects q
* @return double - value of the net force experienced by Charge object Q
*/
public double calcForce(Charge Q, Charge[] q, int numCharges) {
double result;
double[] sum = { 0.0, 0.0 }, tempSum = new double[2];
for (int i = 0; i < numCharges - 1; i++) {
tempSum = calcForceHelper(Q, q[i]); // Help with readability to call
// method helper
fixSigns(Q, q[i], tempSum);
sum[0] += tempSum[0];
sum[1] += tempSum[1];
}
System.out.println("\nOverall force Vector on Q = (" + sum[0] + ")x + (" + sum[1] + ")y.");
result = Math.pow(sum[0], 2) + Math.pow(sum[1], 2);
result = Math.sqrt(result);
double theta = calcTheta(sum);
System.out.print("Force on charge Q by all other charges = " + result + " at ");
if (sum[1] > 0) {
if (sum[0] > 0)
System.out.print((float) Math.round(90 - theta) + " degrees.");
else
System.out.print((float) Math.round(180 - theta) + " degrees.");
} else {
if (sum[0] > 0)
System.out.print((float) Math.round(180 + theta) + " degrees.");
else
System.out.print((float) Math.round(270 + theta) + " degrees.");
}
return result;
}
/**
* Method used to assign negative values to any forces that should be
* negative
*
* @param Q
* Charge - the charge we are focused on
* @param q
* charge - the charge effecting Q
* @param tempSum
* the force vectors we are fixing, if needed
*/
private void fixSigns(Charge Q, Charge q, double[] tempSum) {
if (Q.getQ() < 0 && q.getQ() < 0) {
if (q.getX() > Q.getX())
tempSum[0] *= -1;
if (q.getY() > Q.getY())
tempSum[1] *= -1;
} else if (Q.getQ() > 0 && q.getQ() > 0) {
if (q.getX() > Q.getX())
tempSum[0] *= -1;
if (q.getY() > Q.getY())
tempSum[1] *= -1;
} else {
if (q.getX() < Q.getX())
tempSum[0] *= -1;
if (q.getY() < Q.getY())
tempSum[1] *= -1;
}
}
/**
* Private method used to calculate the angle Theta between two vectors
*
* @param forceVector
* double array - the force vectors we are finding the angle
* between
* @return double - the angle between the two force vectors given
*/
private double calcTheta(double[] vectors) {
double result = Math.abs(vectors[1]) / Math.abs(vectors[0]);// finds
// angle
// between 0
// and 90
result = Math.toDegrees(Math.atan(result));
return result;
}
/**
* Private method used to calculate the force vectors experienced by a
* charged particle
*
* @param radius
* double - distance between two charges
* @param radiusVector
* double array - the radius vectors between two charges
* @param quanOfCharge
* double - the quantity of charge given by k(coulomb's constant)
* * charge of Q * charge of q
* @return double array - the force vectors experienced by two charges
*/
private double[] calcForceVector(double radius, double[] radiusVector, double quanOfCharge) {
double[] result = new double[2];
double theta = calcTheta(radiusVector), magnitude = quanOfCharge;
result[0] = magnitude * Math.cos(Math.toRadians(theta));
result[1] = magnitude * Math.sin(Math.toRadians(theta));
System.out.print("Force Vector = (" + result[0] + ")x + (" + result[1] + ")y.\n");
return result;
}
/**
* private method used to calculate the quantity of charge between two
* charged particles(k * charge of Q * charge of q)
*
* @param Q
* double - the charge in Coulombs of the Charge object Q
* @param q
* double - the charge in Coulombs of the Charge object q
* @return double - the quantity of charge
*/
private double calcCharge(double Q, double q, double d) {
double result;
result = (((Q * q) / (d * d)) * 9E9);
result = Math.abs(result);
System.out.print("Quantity of charge(Q*q*k) = " + result + "\n");
return result;
}
/**
* Private method used to calculate the radius vector between two points on
* a xy-plane
*
* @param x1
* double - x coordinate of the Charge object Q
* @param x2
* double - y coordinate of the Charge object q
* @param y1
* double - x coordinate of the Charge object Q
* @param y2
* double - y coordinate of the Charge object q
* @param radius
* double - distance between the two points
* @return double array - the distance vectors between two charges
*/
private static double[] calcRadiusVector(double x1, double x2, double y1, double y2, double radius) {
double[] result = new double[2];
result[0] = (x2 - x1) / radius;
result[1] = (y2 - y1) / radius;
result[0] = Math.abs(result[0]);
result[1] = Math.abs(result[1]);
System.out.print("Radius vector = (" + result[0] + ")x + (" + result[1] + ")y\n");
return result;
}
/**
* Private method used to calculate the distance between two points on a
* xy-plane using the distance formula or [(x2-x1)+(y2-y1]^(1/2)
*
* @param x1
* double - x coordinate of the Charge object Q
* @param x2
* double - y coordinate of the Charge object q
* @param y1
* double - x coordinate of the Charge object Q
* @param y2
* double - y coordinate of the Charge object q
* @return double - distance between the two points given
*/
private double calcRadius(double x1, double x2, double y1, double y2) {
double distance = Math.pow((x2 - x1), 2) + Math.pow((y2 - y1), 2);
distance = Math.sqrt(distance);
System.out.print("Radius = " + distance + "\n");
return distance;
}
/**
* Main
*
* @param args
*/
public static void main(String[] args) {
Charge Q = new Charge(-.02, .015, -4E-6);
Charge[] q = new Charge[2];
q[0] = new Charge(.035, .005, 3E-6);
q[1] = new Charge(-.0837, .0262, 4E-6);
ElectricForceCalculator calc = new ElectricForceCalculator();
calc.calcForce(Q, q, 3);
}
}
Sample output:
charge Q is -4.0E-6 C at (x,y) = (-0.02, 0.015).
charge q1 is 3.0E-6 C at (x,y) = (0.035, 0.005).
charge q1 is 4.0E-6 C at (x,y) = (-0.0837, 0.0262).
Calculating radius of Q and q...
Radius = 0.05590169943749475
Calculating radiusVector of Q and q...
Radius vector = (0.9838699100999075)x + (0.17888543819998312)y
Calculating quantityOfCharge of Q and q...
Quantity of charge(Q*q*k) = 34.559999999999995
Calculating Force Vector of Q and q...
Force Vector = (34.0025440930528)x + (6.182280744191415)y.
Calculating radius of Q and q...
Radius = 0.06467712114805357
Calculating radiusVector of Q and q...
Radius vector = (0.984892321570454)x + (0.17316788071568426)y
Calculating quantityOfCharge of Q and q...
Quantity of charge(Q*q*k) = 34.4239839545986
Calculating Force Vector of Q and q...
Force Vector = (33.903917474748674)x + (5.96112834720856)y.
Overall force Vector on Q = (0.09862661830412378)x + (-0.2211523969828546)y.
Force on charge Q by all other charges = 0.24214787327038295
