A rocket is shot straight up from a 30-foot
rooftop with an initial velocity of 128 feet
per second. The height, h, of the rocket is
given by the equation h = -16t^2+ 128t+ 30,
where t is the time elapsed in seconds and h
is the height in feet.
a. How long will it take the rocket to
return to the ground?
b. The maximum height that the rocket
achieves is 286 feet. At what time does
it reach that height?