info below)? At a carnival, a new attraction allows contestants to jump off a springboard onto a platform to be launched vertically into the air. The object is to ring a bell located 20 ft overhead. The contestant's height in feet from the springboard is modeled by the function d(t)= -16t^2 -bt +20, where t is the time in seconds after leaving the platform, and b is the takeoff velocity from the platform.