"刚体平面运动基点法举例及加速度分析"

This passage discusses the topic of planar motion of a rigid body in Chapter 9, specifically focusing on the use of the reference point method to determine the acceleration of various points within a plane figure. The process involves selecting a reference point (A in this case) and decomposing the motion into two components: translational motion with respect to the reference point and rotational motion around the reference point. By applying the acceleration addition theorem, the acceleration of point B can be determined in terms of the known acceleration of point A, angular velocity, and angular acceleration. It is important to note that the instant center of acceleration exists but may not coincide with the instant center of velocity, and there is no projection theorem for acceleration. The methodology presented in this passage provides a systematic approach to solving problems related to the acceleration of points within a plane figure, demonstrating the application of fundamental principles in kinematics.