Time is seconds to fall 300 meters?

Question

relevance of gravity on an object to fall 300 meters

Answer 1

Use S = ut + .5 at^2
Where s = displacement (distance in your case 300mts)
u = initial velocity (in this case it is zero
t = time
and a = acceleration (9.8 mts/sec/sec)

Solve the equation yourself.

Answer 2

31 secs, based on constant acceleration due to gravity of 9.8m/s2