Projectile Motion With Air Resistance Vs. Free-Falling with Air Resistance

Hello, I am dealing with two cases.

Case 1:Free-Falling Bullet with Air resistance.

Case 2: Projectile Motion with Air Resistance.

Note: Case 1 is just a special case of Case 2 when vx=0.

My problem is that I cannot add my free-falling bullet to the plot. I have already plotted projectile motion for the bullet.

Here I can provide an example of what the graph should look like:

Also, I would like to know how I can calculate the terminal velocity and the time the bullets reach the ground.

Here is my code:

%clear workspace and command window 
clear
clc


%Constants for Bullet 
    m=0.05; %kg (mass)
    r=0.01; %m (radius)
    C=0.25; %Drag Coefficient of a Sphere
    p=1.2; %kg/m^3 (density of air) 
    A=(pi*(r*2)^2)/4; %m^2 (area of the bullet) 
    b=(p*C*A)/(2*m); %Constant Needed for Drag Calculations
    g=9.81; %m/s^2 (acclereation due to gravity)
    
    %Intitial Conditions 
    delta_t=.001; %s
    h=100; %m (height)
    
    %Case 1: Free-Falling Bullet
    x(1)=0; %m 
    y(1)=100; %m
    v=100; %m/s (velocity)
    
    
    
    %Case 2: Projectile Bullet With Drag
    theta2= 0; %degree
    vx(1)=v*cosd(theta2);
    vy(1)=v*sind(theta2);
    t(1)=0;
    i=1; %Sets Counter/Index
    
    %Start Loop For Projectile Motion with Air Resistance 
    
    while (min(y)> -.0001)
        if vx>0
        ax=-(b/m)*v*vx;
        else
            vx=0;
            ax=0;
        end
       
        ax=-(b/m)*v*vx;
        ay=-g-(b/m)*v*vy;
        v=sqrt(vx^2+vy^2);
        vx=vx+ax*delta_t;
        vy=vy+ay*delta_t;
        
        x(i+1)=x(i)+vx*delta_t+0.5*ax*delta_t^2;
        y(i+1)=y(i)+vy*delta_t+0.5*ay*delta_t^2;
        t(i+1)=t(i)+delta_t;
        
        i=i+1;
    end

plot(x,y,'b'); %Plots Projectile Motion with Drag
xlabel('Horizontal Distance (m)');
ylabel('Vertical Distance (m)');
title ('Projectile Path');
legend('Case 2');

Answer 1

[Sulaymon Eshkabilov]

You can add the free fall plot using simply, e.g.:

...
xfall=x(1)*ones(size(x));
yfall = linspace(0, h, numel(y));
plot(xfall, yfall, 'gh-'), hold on
plot(x,y,'b'); %Plots Projectile Motion with Drag
xlabel('Horizontal Distance (m)');
ylabel('Vertical Distance (m)');
title ('Projectile Path');
legend('Case 1','Case 2', 'location', 'best');