You've got yourself an acute, scalene triangle there.
The distance decreases as the time increases
Answer: Rock require larger drag force and to achieve it rock need to move at a very high terminal velocity.
Explanation: Terminal velocity is defined as the final velocity attained by an object falling under the gravity. At this moment weight is balanced by the air resistance or drag force and body falls with zero acceleration i.e. with a constant velocity.
Case 1: Terminal velocity of a piece of tissue paper.
The weight of tissue paper is very less and it experiences an air resistance while falling downward under the effect of gravity.
Downward gravitational force, F = mg
Upward air resistance or friction or drag force will be 
So, paper will attain terminal velocity when mg =
Case 2: Rock is very heavy and require larger air resistance to balance the weight of rock relative to the tissue paper case.
Downward force on rock, F = Mg
Drag force =
Rock will attain terminal velocity when Mg =
Mg > mg
so,
>
And rock require larger drag force and to achieve it rock need to move at a very high terminal velocity.
Answer:
Relative humidity depends on the amount moisture actually in the air at some temperature to the amount of moisture that the air can hold.
For instance, at 25 deg C the air has a saturation pressure of 23.76 mm of Hg.
That means that if at that temperature the pressure of the water vapor in the air reaches 23.76 mm Hg then the air is 100% saturated.
I believe the standard air pressure at 25 deg C is 760 mm Hg.
Now if the pressure of the water vapor in the air is 1/2 * 23.76 = 11.88 mm then the air is 50% saturated and the relative hunidity is 50 %.
At 100% relative humidity rain occurs (the air can't hold any more water).