If a projectile is launched from a platform 30 feet high with an initial velocity of 128 feet per second, then the height of the projectile at t seconds is given by s(t) = -16t2 + 128t + 30 feet.
(a) At what time does the projectile attain its maximum height? Show some work.
(b) What is the maximum height attained by the projectile? Show some work.