public Ball(int courtWidth, int courtHeight, int INIT_X, int INIT_Y) {
		super(INIT_VEL_X, INIT_VEL_Y, INIT_X, INIT_Y, SIZE, SIZE, courtWidth,
				courtHeight);
		// set img1 to the ball image
		try {
			if (img1 == null) {
				img1 = ImageIO.read(new File(img_file1));
			}
		} catch (IOException e) {
			System.out.println("Internal Error:" + e.getMessage());
		}
		// set img2 to the explosion
		try {
			img2 = ImageIO.read(new File(img_file2));
		} catch (IOException e) {
			System.out.println("Internal Error:" + e.getMessage());
		}
	}