# Intersection between 2 functions describeing falling objects with air drag?

So I got 2 functions, both describing the y position of an object moving with a certain acceleration and air drag(tough a very simplified one) as a function of the time t.

$f_1(t)=y_0-\frac{\ln{(1-k_0v_0(t-t_0))}}{k_0}+\frac{a_0(t-t_0)^2}{2}$

$f_2(t)=y_1-\frac{\ln{(1-k_1v_1(t-t_1))}}{k_1}+\frac{a_1(t-t_1)^2}{2}$

Now I want to get a function that gives me the time when the two objects meet, so when the functions intersect. So basically: t=whatever

I've tried solving it around a bit myself, and I even tried the Wolfram Mathematica of a friend of mine, but with no success.

Any help? Oh and could you include in your answer HOW you get to the solution? I want to understand this, not just get a solution and then forget about it.

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