A 立即获得水平向右的初速度,在 B 上滑动距离工后停下”,说明 A 相对 B 滑行距离为 L。“左边缘再次对齐时恰好相对静止”说明 A 运动到 B 左边缘时两者达到共同速度，此过程相对位移大小也为 L。敲击 A后.A 向右做今减速运动直至停止.B 静止不动:敲击 B 后.B 向右做匀减速运动.A 向右做勾加速运动,直至两者共速后一起减速。解答指导中，生成物体运动过程视频---**Extraction Content:**
**Question Stem:**
11. ★★★ (2019 江苏单科, 15, 16 分) 如图所示, 质量相等的物块 A 和 B 叠放在水平地面上, 左边缘对齐。 A 与 B、B 与地面间的动摩擦因数均为 μ。 先敲击 A, A 立即获得水平向右的初速度, 在 B 上滑动距离 L 后停止下。 接着敲击 B, B 立即获得水平向右的初速度, A、B 都向右运动, 左边缘再次对齐时恰好相对静止, 此后两者一起运动至停止。 最大静摩擦力等于滑动摩擦力, 重力加速度为 g。 求:
(1) A 被敲击后获得的初速度大小 v_A;
(2) 在左边缘再次对齐的前、后, B 运动加速度的大小 a_B、a_B';
(3) B 被敲击后获得的初速度大小 v_B。
**Diagram Description:**
* **Type:** Simple block diagram.
* **Main Elements:**
* Two rectangular blocks, labeled "A" and "B".
* Block A is placed on top of Block B.
* Block B is placed on a horizontal surface depicted with horizontal lines representing the ground.
* The left edges of Block A and Block B are aligned in the configuration shown.
**Other Relevant Text:**
* Question number: 11
* Difficulty rating: ★★★
* Source: 2019 江苏单科 (Jiangsu single subject exam)
* Scores: 15, 16 分 (points)
* Description text: "如图所示" (As shown in the figure)
* Condition: Masses of blocks A and B are equal.
* Condition: Initial position has left edges aligned.
* Condition: Coefficient of kinetic friction between A and B, and between B and the ground, are both μ.
* Condition: First event - A is struck, gets initial horizontal velocity to the right, slides a distance L on B, and stops relative to B.
* Condition: Second event - B is struck, gets initial horizontal velocity to the right, A and B move to the right, left edges align again, and they are relatively stationary at that moment.
* Condition: After the left edges align and they are relatively stationary, they move together until they stop.
* Condition: Maximum static friction equals kinetic friction.
* Constant: Gravitational acceleration is g.
* Request: "求:" (Find:) followed by three sub-questions.
**Sub-questions:**
(1) A 被敲击后获得的初速度大小 v_A; (The magnitude of the initial velocity v_A obtained by A after being struck;)
(2) 在左边缘再次对齐的前、后, B 运动加速度的大小 a_B、a_B'; (The magnitudes of the acceleration of B, a_B and a_B', before and after the left edges are aligned again;)
(3) B 被敲击后获得的初速度大小 v_B。(The magnitude of the initial velocity v_B obtained by B after being struck.)