Distance between two stones dropped 1.31 s apart

[black_hole]

Homework Statement

A stone is dropped from the roof of a high building. A second stone is dropped 1.31 s later. How far apart are the stones when the second stone has reached a speed of 19.3 m/s?

Homework Equations

well...

stone 1
V₀ = 0m/s
v_f = unknown
t = unknown
a = -9.8m/s/s
x = trying to find

stone 2
V₀ = 0m/s
v_f = 19.3m/s
t = unknown
a = -9.8m/s/s
x = trying to find

The Attempt at a Solution

That's all I know.

 

[rl.bhat]

For stone two, find t to reach the velocity 19.3 m/s.
Using the kinematic equation, find the displacement of stone 2.
Find the displacement of stone i in time ( t+1.31s )