[填空题]
A foul ball is hit straight up into a /j98we2 ivj3/qpabdthe air with ay*fuuzhb:7n.ksn9ienp74-gs wu g2/ speed of 30.0 m/s. (use $g=10 \; m/s^2$, only fill in numerical value in the blank) (a.) Calculate the time required for the ball to rise to its maximum height. $s$ (b.) Calculate the time for the ball to fall back to the height at which it was hit. $s$ (c.) Calculate the maximum height reached by the ball. $m$ (d.) Calculate the ball's speed 2 seconds later. $m/s$ (e.) Determine the time at which the ball pass a point 10 m above the point of contact between the bat and ball for the first time. $s$ (f.) Determine the time at which the ball pass a point 10.0 m above the point of contact a second time. $s$
