在光滑水平桌面上有一轻质弹簧，一端固定在墙上 。质量为 m 的小球压缩弹簧另一端，使弹簧弹性势能为 \(E_p\) 。释放后，小球在弹簧作用下从静止开始在桌面运动，与弹簧分离后从桌面水平飞出。小球与水平地面碰撞瞬间，平行地面的速度分量与碰撞前相等，垂直地面的速度分量大小变为碰撞前的 \(\frac{4}{5}\) ，碰撞后弹起最大高度为 h ，重力加速度为 g ，忽略空气阻力 。---**Chart/Diagram Description:** * **Type:** A physics diagram illustrating a system with a mass and spring. * **Main Elements:** * **Wall:** A vertical surface is depicted on the far left, indicated as a fixed support by diagonal hatching lines. * **Spring:** A horizontal coiled spring is shown. Its left end is attached to the fixed wall. * **Sphere/Ball:** A small, grey, spherical object (a ball or mass) is attached to the right end of the spring. * **Table/Platform:** A rectangular, brown, flat surface (a table or platform) extends horizontally from the wall towards the right. The spring and the ball are resting on top of this surface. * **Table Leg:** A vertical support leg extends downwards from the right side of the table. * **Ground/Base:** A horizontal surface, indicated by diagonal hatching lines, is depicted below the table, representing the ground or a stable base on which the table leg rests. * **Relative Position and Direction:** The wall is on the left. The spring is horizontal, connecting the wall to the ball. The spring and ball system rests on the top surface of the table. The table is supported by a vertical leg which stands on the ground. The ground is positioned below the table.