The word that could fit to this is Text Mining. This word also referred to as text data mining, roughly equivalent to text analytics, a process of deriving high-quality information from text. This high quality information derived through the devising of patterns and trends through means such as statistical patter learning.
The time must be measured with respect to gravity. As it falls, it has free fall that is the force acting on it will be the gravity.With the distance in account, d = 1/2 gt²
t = √(2d/g)
I believe this is known as wave period.
hope this helps!