Given
Total height of the building, H=14 m
The initial velocity is v=-2 m/s
The point B is at height, h=4 m.
To find
The time need by the stone to reach point B.
Step-by-step explanation
Using the equation of kinematics,
where y is the distance covered.
t is the time taken
Thus,
Conclusion
The time is 1.28 s