Pls help asap, this is due pretty soon

5.2 seconds

Step-by-step explanation:

h(t) = -16t^2 +64t+100

Let h(t) =0

0 =  -16t^2 +64t+100

Factor out -4

0 = -4( 4t^2 - 16t -25)

Divide by -4

0 = ( 4t^2 - 16t -25)

Using the quadratic formula

-b ±sqrt( b^2 -4ac)

    2a

16 ±sqrt ( (16)^2 - 4(4)(-25))

  2(4)

16 ±sqrt ( 256 +400)

  8

16 ±sqrt ( 656)

  8

16 ±4sqrt ( 41)

  8

2 ±1/2 sqrt ( 41)

5.2 and -1.2

We cannot have negative time so

5.2