Question

The altitude of an object, d, can be modeled using the equation below. d=-16t^2+vt+h From the edge of a 486-foot cliff, Peyton shot an arrow over the ocean with an initial upward velocity of 90 feet per second. In how many seconds will the arrow reach the water below?

Answer 1

Answer:

9 seconds

Step-by-step explanation:

d=-16t²+vt+h

The water level will be at 0 level (distance = 0)

0 = 16t² - 90t - 486

8t² - 45t - 243 = 0

(t - 9) (8t + 27) = 0

t = 9 or t = -27

since time should be a positive number, so t = 9 second