As we have seen previously, the height reached by a thrown ball as a function of time is

h(t) = 32t - 16t²

h'(t) = 32 - 32t

h"(t) = -32

h"'(t) = 0

h"(t) < 0

The rate of change of velocity is negative.

h'(0) > h'(1) > h'(2), h(t) curves down.