Question 1194440
A quarter is dropped from the top of the Eiffel Tower.  Determine amount of time until quarter hits the ground.

Height of tower; 984 ft.

Quarter mass; 5.67 grams.

Check my calculations, please.

S = 16t^2

984 = 16t^2

984 - 16t^2 = 16t^2 - 16t^2

-16t^2 + 984 = 0

-16t^2 + 984 - 984 = 0 - 984

-16t^2 =  -984


-16t^2 / -16 = -984 / -16

t^2 = 61.5

Taking square root:

t =  + 7.84, - 7.84

t = 7.84 sec.

Not sure if I used correct formula.
===========================
You added several "steps" that accomplished nothing.
984 = 16t^2

984 - 16t^2 = 16t^2 - 16t^2

-16t^2 + 984 = 0

-16t^2 + 984 - 984 = 0 - 984

-16t^2 =  -984  *****  This is where you started.
===================
If air resistance is neglected, the mass is not relevant.