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?

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

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116