Terminal Speed

If you knew the numerical values needed, how would you calculate the net force exerted on the ball shown in the figure?

A falling object downward speed increases, so does air resistance.  Thus, there comes a time when air resistance equals the weight of the object.

As the downward speed of a falling object 1($), so does air resistance.  Thus, there comes a time when air resistance 2($) the weight of the object.  At this speed the object no longer 3($), but instead it continues at the same 4($).  (This follows from F = ma, since if the net force is 5($), the acceleration must also be 6($).)  The final speed attained is called the object's 7($).

Consider a falling rock at a time when it is traveling at just less than terminal speed.  Will its acceleration be less than, equal to, or more than 9.8 m/s² at this time?