Find the time, t, in seconds it takes for an object to fall from the top of a 1600 ft building by using the function h = -16^2 + 1600 (hint: set h=0).

The reason we set h equal to 0 is because h is height, and of course the height of an object when it is on the ground is 0.  That looks like this then: .  To make this easier to factor, aka solving it for the time it takes to hit the ground, we will factor out a -16.  That gives us this: .  That means that, by the Zero Product Property, either -16=0, or .  Of course , so that means that .  We add 100 to both sides to get .  Taking the square root of both sides, t = -10 and t = 10.  The 2 things in math that will never EVER be negative are time and distance/length, so that means that -10 seconds is out.  Therefore, t = 10 seconds.