Question

A stone is dropped from the top of a 83.0 m tall building. How far above the ground is the stone 1.60 seconds before it reaches the ground?

Answer 1

first how long before it hits ground?
83 = 4.9 t^2
t = 4.12 s

so it fell for 4.12 - 1.60 = 2.52 seconds
so how far did it fall in 2.52 seconds?
d = 4.9*(2.52)^2 = 31 meters
so it is
83 - 31 = 52 meters up