论文标题
关于刚体的平面运动教学
About the Teaching of Plane Motion of Rigid Bodies
论文作者
论文摘要
对飞机上刚体的运动的研究（RBP运动）通常是学生在入门物理课程中面临的最具挑战性的主题之一。在本文中，我们讨论了一些通常在基本物理课程中使用的问题，以突出与RBP运动有关的某些方面，这些方面通常不会被物理学专业的学生很好地理解。第一个问题是由杆和圆盘组成的摆。钟摆的角频率在两种情况下计算：固定在杆和圆盘上的圆盘免费旋转。给出了从一个情况到另一种情况的角频率变化的详细说明。第二个问题是梯子滑动触摸无摩擦表面。我们使用此问题来强调这样一个事实，即尽管梯子的总机械能得到了保守，但表面施加的接触力执行转换和旋转工作。
The study of the motion of a rigid body on a plane (RBP motion) is usually one of the most challenging topics that students face in introductory physics courses. In this paper, we discuss a couple of problems which are typically used in basic physics courses, in order to highlight some aspects related to RBP motion which are not usually well understood by physics students. The first problem is a pendulum composed of a rod and disk. The angular frequency of the pendulum is calculated in two situations: disk fixed to the rod and disk free to spin. A detailed explanation of the change in the angular frequency from one case to another is given. The second problem is a ladder which slides touching a frictionless surface. We use this problem to highlight the fact that the contact forces applied by the surface perform translational and rotational work despite that the total mechanical energy of the ladder is conserved.
