import numpy as np
import matplotlib.pyplot as plt
alphaV=1*10**(-3)
h0=1.5
deltat=0.1
g=9.81

T=[0]
H=[h0]
while H[-1]>0:
    T.append(T[-1]+deltat)
    H.append(H[-1]-deltat*alphaV*(2*g*H[-1])**(1/2))
plt.plot(T,H)
plt.show()