2. The equation h=-5t? + 20t + 1 models the height, h metres, of a baseball as a function of time, t seconds, since it was hit. The ball
hit the ground before a fielder could catch it
(a) How long was the baseball in the air, to the nearest tenth of
a second? (2 decimal places)
(b) For how many seconds was the height of the ball at least
16m? (2 decimal places)