今年全国高考物理试卷第25题为:“质量为m的钢板与直立轻弹簧的上端连接,弹簧下端固定在地上.平衡时,弹簧的压缩量为x_0,如图所示.一物块从钢板正上方距离为3x_0的A处自由落下,打在钢板上并立刻与钢板一起向下运动,但不粘连.它们到达最低点后又向上运动.已知物块质量 This year’s national physics examination paper No. 25 is entitled: ”The mass of m steel plate is connected with the upper end of the upright light spring, the lower end of the spring is fixed on the ground. When the balance, the compression of the spring is x_0, as shown in the figure. A block from Immediately above the steel plate at a distance of 3x_0 from the free fall, hits the steel plate and immediately moves down with the steel plate, but does not stick. They reach the nadir and then move upward again. Known block quality