Question

A rock is thrown from the top of a building. The height s (in feet) as a function of time (in seconds) can be modeled by the function

s(t) = -16t² + 3000
Approximately when will the rock be 1,976 feet above the ground.
O a
Ob
C
8 sec
135 sec
85 sec
15 sec

Answer 1

Answer: the rock will be at a height of 1,976 feet above the ground after approximately 8 seconds

Explanation:

We can start by setting the height function equal to 1,976 and solving for t:

-16t² + 3000 = 1976

Subtracting 1976 from both sides, we get:

-16t² + 1024 = 0

Dividing both sides by -16, we get:

t² - 64 = 0

Factoring, we get:

(t + 8)(t - 8) = 0

So t = 8 or t = -8. We can ignore the negative solution since time cannot be negative.

Therefore, the rock will be at a height of 1,976 feet above the ground after approximately 8 seconds.

Answer: (A) 8 sec