Answer
The equation for car speed without the wind effects is:
$v_{car} = \frac{1}{2}(\frac{d}{t1} + \frac{d}{t2})$
Work Step by Step
To eliminate the wind effects, consider the wind blowing alongside the car during the time $t1$ and blowing opposite during $t2$ with the same distance $d$, we have:
$d/t1 = v_{car}+v_{wind}$
$d/t2 = v_{car}-v_{wind}$
By adding the two equations and dividing by 2, we obtain:
$v_{car} = \frac{1}{2}(\frac{d}{t1} + \frac{d}{t2})$
Thus, we find the car speed without the wind effects.
