请描述一下小球的运动轨迹---**Question Stem:** 14. 如图 1-77 所示, 一条不可伸长的轻绳长为 L, 一端用手握住, 另一端系一质量为 m 的小球, 今使手握住的一端在水平桌面上做半径为 R、角速度为 ω 的匀速圆周运动, 且使绳始终与半径 R 的圆相切, 小球也将在同一水平面内做匀速圆周运动, 若人手做功的功率为 P, 求: **Diagram Description:** * **Type:** Schematic diagram illustrating circular motion. * **Main Elements:** * Two concentric circles are shown. * The inner circle has radius R and represents the path of the hand. Its center is the center of the entire motion. * The outer circle represents the path of the small ball. * A point labeled 'R' is shown on the inner circle, representing the position of the hand. * An arrow indicates angular velocity ω around the center of the circles, suggesting the rotation direction. * A line segment labeled 'L' connects the point 'R' on the inner circle to a point labeled 'm' on the outer circle. This line segment represents the string of length L. * The line segment 'L' is shown tangent to the inner circle (radius R) at the point 'R'. * The point 'm' represents the small ball of mass m. * An arrow points along the tangent direction of the outer circle at the position of 'm', suggesting the velocity direction of the ball. **Sub-questions:** (1) 小球做匀速圆周运动的线速度大小. (2) 小球在运动过程中所受到的摩擦力的大小.