Question

Samantha threw an apple out of a window from the tenth floor of her apartment building. The equation y=-16t^2+120 can be used to represent the fruits height above the ground, where t represents time, in seconds, after she threw the Apple. How long did it take the Apple to hit the ground?

Answer 1

To hit the floor means the height is 0

-16t^2 + 120 = 0
-16t^2 = -120
t^2 = 7.5
t = 2.74