Comments on Differential equation solution cannot describe what happens in reality
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Differential equation solution cannot describe what happens in reality
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Suppose we have a free falling object inside a planet's gravitational field with strength g.The planet's atmosphere provides a drag force which is dependant from the u^2 of the particle.
Suppose the weight of the object is m1g and the drag force due to the atmosphere is -ku^2 and lets say we set k=1 for simplicity we end up with this differential equation:
$$\frac{du}{dt} = g+\frac{u^{2}}{m_{1}} $$
and if you solve the differential equation with initial condition u(0)=0 you get
$$u(t) =\frac{\sqrt{g}}{\sqrt{m_{1}}}\cdot tan(\sqrt{g}\sqrt{m_{1}}t) $$
If I graph the function in Desmos it shows me this
However we have infinities involved and I dont think it is right.What am I missing?
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