A rock is dropped from a 196-m-high cliff. How long does it take to fall (a) the first 98.0 m and (b) the second 98.0 m?

Answer 1

h= gt²/2
t=sqrt(2h/g) = sqrt(2•196/9.8)=6.32 s.
The first 96 m
h/2=gt₁²/2
t₁=sqrt(h/g)=sqrt(196/9.8)=4.47 s.
The 2nd 96 m

t₂=t-t₁=6.32-4.47 =1.85 s