public void drawBalls(Graphics g){
    for(int i = 0; i < numBalls; i++) {
        int x = (int)Math.random() * 650; int y = (int)Math.random() * 200;
        Ball ball = new Ball(x,y,50,h,v);
        g.fillOval(ball.getX(),ball.getY(),ball.getR(),ball.getR());
    }
  }