package phys2d;

/**
 * Last edit 060914 @ 0500
 */

import javax.swing.JFrame;

import phys2d.panels.Phys2DPane;


public class Phys2DMain {

	private static JFrame mainPhys2dFrame = new JFrame("Physics 2D"); 
	public static final int XRES = 1000;
	public static final int YRES = 1000;
	private static final int updateRate = 50;
	private static final int maxFps = 200;
	private static final int maxFramesSkippable = 5;
	
	public static void main(String[] args) {
		
		mainPhys2dFrame.setSize(XRES, YRES);
		mainPhys2dFrame.setResizable(false);
		mainPhys2dFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		mainPhys2dFrame.add(new Phys2DPane(updateRate, maxFps, maxFramesSkippable));
		mainPhys2dFrame.setVisible(true);
		
	}
}

package phys2d;

/**
 * Last edit 210515
 * Success!
 */

import javax.swing.JFrame;

import phys2d.panels.Phys2DPane;


public class Phys2DMain {

	private static JFrame mainPhys2dFrame = new JFrame("Physics 2D"); 
	public static final int XRES = 1000;
	public static final int YRES = 1000;
	private static final int updateRate = 50;
	private static final int maxFps = 200;
	private static final int maxFramesSkippable = 5;
	
	public static void main(String[] args) {
		
		mainPhys2dFrame.setSize(XRES, YRES);
		mainPhys2dFrame.setResizable(false);
		mainPhys2dFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		mainPhys2dFrame.add(new Phys2DPane(updateRate, maxFps, maxFramesSkippable));
		mainPhys2dFrame.setVisible(true);
		
	}
}

Test commit