题目10：一球从100米高度自由落下，每次落地后反跳回原高度的一半；再落下， 求它在第10次落地时，共经过多少米？第10次反弹多高？ -Topic 10: a ball from 100 meters height free fall, every time after landing bounce back half of the original height To fall, For it in the 10th born, a total of how many