Question

from the top of the building 256 ft high an object is thrown vertically upward with an initial velocity of 96 ft/sec. when will it strike the ground?

Answer 1

$h(t)=256+96t-16t^2.$

$h(t)=0\to t^2-6t-16=0\to t=8\;sec.$

An object strikes the ground in 8 seconds.