Question (need in 40 minutes or so thanks)

909 7 A paper-mache rocket is thrown by Angela from the roof of her school. Its flight path is modelled by h(t) = -5t2 + 30t + 10, where h is the height of the rocket above the ground in meters and + is the time after the launch in seconds. a) How high was the roof that Angela was standing on before throwing the rocket? What is the highest her rocket will go? b) If her friend David is climbing the 100m flag pole and is at the top of the pole, is there a chance that Angela's rocket will hit him