"Question - Isn't it true that, on earth, where no object really falls "freely", there is a point at which the falling object finally attains zero acceleration? That is, could you say that, in reality, a falling object attains a maximum velocity above which it will not go?"
You are absolutely correct! Gravity accelerates an object high up in the air downward at the usual rate of 32 ft/second/second. As it accelerates, however, the air resistance increases, roughly like speed at low speeds and then more like the square of the speed. Finally, the air resistance exerts an upward force exactly equal and opposite to the force of gravity. The object will then continue to fall at that speed, which is called the terminal speed.
For a person in free fall, the terminal speed is about 60 m/s or 135 miles/hour. When his parachute opens (hopefully), the terminal speed is reduced to around 12 miles/hour.
Best, Dick Plano, Professor of Physics emeritus, Rutgers University
http://www.newton.dep.anl.gov/askasci/phy00/phy00800.htm
Terminal velocity will be a higher speed at higher altitudes due to the thinner air. At low altitudes, your figure is correct.
What is the air resistance “WAY UP THERE” ?? Is the normal terminal speed much higher?