Question

Can someone please read that and give me an answer, i’ve been stuck on it for awhile.

Answer 1

Answer:

after 21 seconds

Step-by-step explanation:

Given

h = - 16t² + 272t + 1344

When the ball strikes the ground then h = 0, that is

- 16t² + 272t + 1344 = 0 ( divide through by - 16 )

t² - 17t - 84 = 0 ← in standard form

(t - 21)(t + 4) = 0 ← in factored form

Equate each factor to zero and solve for t

t - 21 = 0 ⇒ t = 21

t + 4 = 0 ⇒ t = - 4

However t > 0 thus t = 21

The ball strikes the ground after 21 seconds.