Question

An object is dropped from a height of 400 feet. The amount of time, in seconds, the object takes to hit the ground can be found by solving the equation -16t^2+400=0 . How many seconds will it take to hit the ground?

Answer 1

-16t^2+400=0

16t^2=400

take square root on both sides.

$\sqrt{16t^2} =\sqrt{400}$

4t=20

t=20/4

t=5