Question

Someone please help T.T I need help ASAP

Answer 1

Step-by-step explanation:

Given that,

The quadratic equation that models the ball's height above the ground h, t seconds after it was thrown is given by :

$h=-16t^2+108t+28$ ...(1)

(a) For maximum height, put dh/dt = 0

So,

$\dfrac{d(h)}{dt}=\dfrac{d}{dt}(-16t^2+108t+28)=0\\\\-32t+108=0\\\\t=\dfrac{108}{32}=3.37\ s$

Put the value of t in equation (1).

So,

$h=-16(3.37)^2+108(3.37)+28\\\\h=210.24\ ft$

(b) When the ball reaches the ground,

h = 0

So,

$-16t^2+108t+28=0\\\\t=7\ s$

So, the ball hits the ground in 7 seconds.