解方程或化简
现从某一水池水面上方h=0.8m高处,让硬质小球自由下落,小球从释放到入水后减速为零共用时t=0.6s,该水池水深H=0.8m,不计空气,取g=10m/s2.求
—When is the ______ time to go to Dalian?
—Spring.
--OK, I won't. We should save electricity.