Question

The height of a projectile fired upward is given by the formula
s = v0t − 16t2,
where s is the height, v0 is the initial velocity, and t is the time. Find the time for a projectile to return to Earth if it has an initial velocity of 184 ft/s.
____________ s

Answer 1

Different initial up speed but use :
http://www.jiskha.com/display.cgi?id=1396965991#1396965991.1396967805

Answer 2

if Sam fires a bullet straight upward with an initial velocity of 128 ft/sec, the height h of the bullet above the ground t sec after it is fired can be modeled by the equation h(t)=-16(t-4)^2+259