Given,
Rate of free fall = 216 km/h
Solution,
km/h to m/s is converted as follows :

So, the rate of fall is 60 m/s.
If t = 20 s
Assume, initial velocity = 0
It will move under the action of gravity.
Using equation of motion,

Hence, this is all for the solution.
Remember that there is 100 centimeters in a meter, and 1000 meters in a kilometer. If you multiply both values together (so you have a conversion of centimeters to kilometers) you get 100,000. Therefore, 100,000 centimeters makes a kilometer. Divide 320,000 by 100,000 and you get 3.2. Therefore, a centimeter would represent 3.2 kilometers.
Answer: Answers and work are all in the picture that I attached. Hope this helps