Question

If a football player passes a football from 4 feet off the ground with an initial velocity of 36 feet per second, how long will it take the football to hit the ground? Use the equation h = -16t2 + 36t + 4.
A. quantity of 9 plus or minus square root of 65 all over 8
B. 9 plus or minus square root of 65 end root over 8
C. quantity of 9 plus or minus square root of 97 all over 8
D. 9 plus or minus square root of 97 end root over 8

Answer 1

Answer:

D ) h₁,₂  =[ ( 9 ± √97 ) ]/8

Step-by-step explanation:

The equation of the football is

h =  -16t²  + 36t +4

What is the time for football to hit the ground

Hit the ground means     h = 0  then

-16t²  +  36t  +  4  =  0

Simplifying by (-4)

4t²  -  9t   - 1  =  0   a second degree equation

Solving

h₁,₂  =[ ( 9 ± √(81 + 16) ] /8        ⇒  h₁,₂  =[ ( 9 ± √97 ) ]/8

The answer given in  D