Using air resistance (drag) in Python calculation

Question

I am simulating a free fall with a function that needs to calculate the time it takes for a particular object to reach the surface, I got this program working without accounting for air resistance.. the force of air resistance(drag) is: 0.24 * v^2
Im not sure what I'm doing wrong or how I can make it work, any help would be appreciated
def jump():

t = 0
    dt = 0.01
    v = 0
    x = 728   #starting height
    a = 9.8
    
    while x > 0:
        x = x - v*dt
        t = t + dt
        a = 9.8 - 0.24*(v**2)*dt #drag coefficient and calculation
        v = v + a*dt

return round(t, 1)

result = jump()
print(result)

Output: 15.9 seconds, but it needs to be 17.2. Maybe its going wrong with the velocity updating after the acceleration?

Flight_101 · Answer

You have not factored in mass: you state in your question that the force of drag is 0.24*v^2. In your code, however, you use this as an acceleration, applying it alongside the 9.8 from gravity. This only works if the mass is one kilogram.
Modifying your function to take mass as an argument:
def jump(mass):

t = 0
    dt = 0.01
    v = 0
    x = 728   #starting height
    a = 9.8
    
    while x > 0:
        x = x - v*dt
        t = t + dt
        a = 9.8 - (0.24*(v**2)*dt)/mass #drag coefficient and calculation
        v = v + a*dt

return round(t, 1)

If we parse mass as 0.73 kg, we get
>>> jump(0.73)
17.2

Using air resistance (drag) in Python calculation

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