Question

A ball is thrown from 4 feet off the ground with a vertical velocity of 30 feet per second.

Answer 1

A ball is at it maximum height when its velocity is zero.  y = 4+30t - 16t^2 is the formula, where
V = V(0) -32t
0 = 30- 32t
t = 15/16 seconds when its velocity is zero.
It is not at its maximum height but is falling.