I'm very very new to coding and I'm currently trying to make a model of a rocket flight. In the model in need to calculate the rocket's speed but therefore I need to know the air resistance which is determined by the speed of the rocket. So my problem is that I'm trying to calculate a value for which I need the value itself. My solution to the problem was to take the previous value of the speed to determine the air resistance and calculate the new speed. I need to do the same for my h (Height)

Velocity = (( F_Rocket - ( F_Drag + F_Gravity ) / m ) t.

This is the formula that I'm using to calculate the speed, I derived it from

F_resulting = F_Rocket - (F_Drag + F_Gravity)

T0 = 288.15 #temperature needed for the air density

q1 = -0.0065 #constant

e = 2.718281828459

p0 = 101325 #base pressure

g = 9.80665 # gravity 

R = 287.00 # gas constant

G = 6.67259 * (10 ** -11) # gravity constant

m1 = 5.972 * (10 ** 24) #mass earth

m2 = 0.070 #mass rocket (mini plastic rocket)

rAarde = 6371000 #radius earth

Cw = 0.14

A = 0.00053913

F_Rocket = 0.22

t = 0 # this is time



while t <= 50: #the while loop is expressed in time

    T1 = T0 + q1 * (h - h0)

    print('T1 = ', T1, 'K')

    p1 = p0 * ((T1 / T0) ** ( -g / (q1 * R)))

    rho1 = p1 / (R * T1)

    F_Drag = 0.5 * A * Cw * rho1 * (v_old ** 2) # This v needs to be one from the previous loop, I will also need some starting point

    v_new = ((F_Rocket - (F_Drag + F_Gravity) / m) * t

    h_new = v_old * t

    F_Gravity = G * ((m1 * m2) / (rAarde + h_old))

    print(Drag1, 'N')

    print(rho1, 'Kg m^-3')

    print(p1, 'pa')

    t += 1;

I just need to get the values of previous answers like in a recursive formula. If someone could explain me how to get that coded, that would be great.

Initialize a velocity variable (vel) outside of the while loop. Update it to the new value only after calculating F_Drag

vel = 0   # pick an appropriate starting value



while t <= 50:

   ....

   F_Drag = 0.5 * A * Cw * rho1 * (vel ** 2)        

   vel = ((F_Rocket - (F_Drag + F_Gravity) / m) * t

   ....

Now every time you go into the loop vel will be the previously calculated value for F_Drag, then you update it using the F_Rocket equation.