The given equation represents the distance travelled by the object at time t.
The given equation is expressed as
-16t^2 + 48t + 160
At the point where it hits the ground, the distance woule be 0. Thus, we would so;ve the equation,
-16t^2 + 48t + 160=0
We would divide through by - 16. We have
t^2 - 3t - 10 = 0
We would find two terms such that their sum or difference is - 3t and their product is - 10t^2. They are 2t and - 5t. We have
t^2 + 2t - 5t - 10 = 0
By factorising, we have
t(t + 2) - 5(t + 2) = 0
(t + 2)(t - 5) = 0
t + 2 = 0 or t - 5 = 0
t = - 2 or t = 5
Since the time cannot be negative, the correct answer is
time = 5 seconds