void update_coordinate_rome(double &x, double &y, double v_x, double v_y, double t) {

	x = x + v_x * t;
	y = y + (v_y * t - (0.5) * (9.81) * pow(t,2));

}

void update_coordinate_vis(double &x, double &y, double v_x, double v_y, double t) {
	x = x + v_x * t;
	y = y + (v_y * t - (0.5) * (9.81)* pow(t,2));

}

double distance(double x1, double y1, double x2, double y2) {
	double distan;
	distan = sqrt((pow((x1-x2),2) + pow((y1-y2),2)));
	return distan;