Where Can I Find Help Understanding Kinematics Equations for Pelican Diving?

[yoyo2112]

Homework Statement

Pelicans tuck their winds and free fall straight down when diving for fish. Suppose a pelican starts its dive form a height of 20.0 m and cannot change its path once commited (uniform motion). If it takes a fish 0.1 s to perform evasive action, at what min height must it spot the pelican in order to escape

Homework Equations

No Clue

The Attempt at a Solution

Stumped

I have tried in numerous times but was away for a lesson and don't have a clue to what is going on

Please Help

 

[rl.bhat]

Find the time t taken by the pelican to reach the water from 20 m.
Then find the distance covered by the pelican in (t - 0.1) seconds. And proceed.

 

[206PiruBlood]

You will need $$s=y_{i}+v_{i}t+\frac{1}{2}at^{2}$$

How long does it take the pelican to free fall to the water? How much time before that must the fish react?

 

[yoyo2112]

OO thanks for the reply guys. Do you know where i can get a list of all these equations (kinematics)

 

[206PiruBlood]

Do you have a textbook?