[填空题]
A foul ball is hit s ubv 5+jpiez tbkk29pq 0.t*j,d b0ny; vfov uqp3rl54/4w6fgtraight up into the air with a speed of 30.0 m/s. (only fill in numerical valvfp4;g f b530wryq dul no46/vue in the blank)
(a.) Calculate the time required for the ball to rise to its maximum height. $s$
(b.) Calculate the maximum height reached by the ball. $m$
(c.) Determine the time at which the ball pass a point 25.0 m above the point of contact between the bat and ball for the first time. $s$
(d.) Determine the time at which the ball pass a point 25.0 m above the point of contact a second time. $s$