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1. Algebra solution
The formula for the height of a freely falling body under gravity force, that students learn and use in their Algebra exercises is
H(t) = + ,
where g = 32 ft/s^2 and h0 is the initial height (in feet).
In this case, h0 = 1400 ft, therefore the equation to find the time t is
H(t) = 0, or = 0, which is equivalent to
16*t^2 = 1400, which implies t = = 9.35 seconds.
Answer. 9.35 seconds.
2. Physics solution
In school Physics course, the students learn the formula for the distance which a freely falling body travels
vertically down under the gravity force
H(t) = .
where the included parameters were all explained in the Algebra solution.
To find time, get from this formula t = = = 9.35 seconds,
and you get the same answer.
These are two standard, simplest and straightforward methods of Algebra and Physics to solve the problem.
What the tutor @amalm proposes in his post, is never used, and I do not recommend you to take it seriously.
Only the person who doesn't know basics, can propose this approach.