A gust of wind forces a rock to fall off a cliff that's 20 feet high. This is represented by the function h(t) = –16t2 + 20, where t represents the time measured in seconds, and h represents height above the ground. Approximate how many seconds it takes for the rock to hit the ground. Answer Options:

A.) 1.25 seconds

B.) 1.5 seconds

C.) 1.12 seconds

D.) 1 second

C.) 1.12 seconds

Step-by-step explanation:

Hi, to answer this question we have to substitute h=0 (when the rock hits the ground the height above it is 0) in the equation given:

h (t) = –16t2 + 20

Solving for t (time)

0= –16t2 + 20

16t2=20

t2=20/16

t=√1.25 =1.12 seconds (option C)

Feel free to ask for more if needed or if you did not understand something.

the height of the surface increases from the center out to the sides of the road

it is c!