C.Air pressure is lower between the buildings
hope that helps :)
Systematic is just a certain way of doing something it refers to the scientific method or how theories are proved in science by repeating scientific method over and over again
Let t=time to reach the ground=8 secs, g= acceleration of gravity. The speed v on reaching the ground is gt=8g=78.4 m/s where g=9.8 m/s/s approx.