第21题: [单项选择]小球从3米高处落下,被地板反向弹回,在1米高处被接住,则小球的() A. 位移为2米,方向向下 B. 位移为1米,方向向上 C. 路程为4米,方向向下 D. 路程为2米,路程是标量 参考答案:A 答案解析:小球从3m高处落下被地板弹回1m高处,运动轨迹的长度是路程,等于4m,路程是标量,没有方向;从起点到终点的有向线段的长度是位移大小,等于2m,方向向下.
故选A
第25题: [单项选择]What is wrong with the woman’s TV A. The repairman borrowed it. B. It needs repairing. C. It is too old. 参考答案:B 答案解析:[听力原文] M: The TV show was so funny last night. W: My TV is in the repair shop. Q: What is w