Hi,
 h=  -16t^ + 112t    Note: 
 h =  -16(t-7/2)^2 + 16*49/4
  h =  -16(t-7/2)^2 + 196  
Note: vertex form of a Parabola opening up(a>0) or down(a<0), 
 
where(h,k) is the vertex  
Parabola opening Downward  V(3.5,196)
how long will it take for the object to reach it's maximum height?  
 will take 3.5 sec to reach max height of 196 ft