At some speed, the drag or force of resistance will equal the gravitational pull on the object. At this point the object ceases to accelerate and continues falling at a constant speed called the terminal velocity (also called settling velocity).
C. I did it bit i forgot how I did it
You are currently converting Distance and Length units from Centimeters to Feet 321 Centimeters (cm) = 10.5315 Feet (ft) This is a hard one but see if this helps if not let me now and i can try again..
One of the components that affect the period is gravity (the other is length). This gravity is basically the value of the effective acceleration that acts on the body due to gravity. When the elevator is over free fall, the effective gravity becomes zero. Mathematically this can be visualized as,

Since this value is zero, the period would tend to be infinite,

Therefore the frequency that is inversely proportional to the period would be defined as



In this way there is no frequency on the body which will not generate any oscillation on the body