Question

Number 15, I need help please.

Answer 1

so first you plug in for the seconds
so for 1 second

`h = - 16t + 144 \\ h = ( - 16)(1) + 144 \\ h = - 16 + 144 \\ h = 138`
now for 2 seconds

`h = - 16(2) + 144 \\ h = - 32 + 144 \\ h = 112`
now for 3 seconds

`h = - 16(3) + 144 \\ h = - 48 + 144 \\ h = 96`

to find when the ball hits the ground plug in 0 for h

`0 = - 16t + 144 \\ - 144 = - 16t \\ ( - 144)/( - 16) = ( - 16t)/( - 16) \\ t = 9`
answer is 9 seconds

Answer 2

The answer is three seconds because that's when 144 and -144 cancel out and gets 0 which is surface level.