# create new arrays
Adat = [0]  #acceleration
Vdat = [0]  #velocity
Zdat = [0]  #height


V0 = 0
Vdat[0] = V0        #set initial conditions

Z0 = 30000
Zdat[0] = Z0

T = 0

t_step = 0.9  #set time step in seconds

b = 0.5  #drag coefficient in kg/s

while Zdat[-1] >= 0:
    A1 = (-m*g-b*np.abs(V0)*V0)/m
    V1 = V0+A1*t_step
    Z1 = Z0+V1*t_step
    T = T + t_step
    Adat.append(A1)
    Vdat.append(V1)
    Zdat.append(Z1)
    V0 = V1
    Z0 = Z1