Answer:
After 2 seconds
Step-by-step explanation:
First step is find an equation of velocity:
h(t)=-16t2+64t+112. The velocity function is derivated from position function, so we should do that.
v(t)= h´(t)= -16*2*t+64 ⇒ v(t)= -32t+64.
Now we know the arrow reach the maximun height when this velocity is equal to zero when t>0.
0=-32t+64 ⇒ 32t=64, split each member for 32 ⇒ =
t=2. That means after 2 sec. the arrow reach the maximum height