# Using air resistance (drag) in Python calculation

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?

• Why is there a dt in the acceleration equation? – Brain Stroke Patient Oct 10 at 9:11
• Good question.. I didnt have this before, but I saw it somewhere in someones code with a similar issue , turns out it does come closer to the answer – Casper A Oct 10 at 9:12