Physics: I am having problems with this physics problem about reaction time?

Question

A meterstick is held vertically above your hand, with the lower end between your thumb and first finger. On seeing the meter stick released, you grab it with those two fingers. You can calculate your reaction time from the distance the meterstick falls, read directly from the point where your fingers grabbed it.

If the measured distance is 18.1 , what is the reaction time?

The correct answer involves the variable g.

Answer 1

Assuming you mean 18.1 cm.
x = at^2/2 ==> t = sqrt(2x/a)
a = g = 9.81 m/s^2
2x = 0.362
t = 0.1921 s.