Circular motion is embedded in many circus tricks, and is also one of the most challenging topics for both students and teachers. Previous studies have identified several misconceptions about circular motion, and especially about the forces that act upon a rotating object. A commonly used demonstration of circular motion laws by physics teachers is spinning a bucket full of water in the vertical plane further explaining why the water did not spill out when the bucket was upside down. One of the central misconceptions regarding circular motion is the existence of so-called centrifugal force: Students mistakenly believe that when an object spins in a circular path, there is real force acting on the object in the radial direction pulling it out of the path. Thus, one of the most frequently observed naïve explanations is that the gravity force mg is compensated by the centrifugal force on the top of the circular trajectory and thus, water does not spill down. In the present study we decided to change the context of the problem from a usual physics class demonstration to a relatively unusual informal environment of a circus show and investigate the spectators’ ideas regarding circular motion in this context. Thus, the goal of the present study is to examine the concepts of a heteroaged population regarding circular motion phenomenon provided in the context of a circus number as expressed in focus-group interviews following the number.

中文翻译：

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在马戏团中识别物理学的误解：圆周运动的情况

圆周运动嵌入了许多马戏团的技巧，对于学生和老师来说，这也是最具挑战性的主题之一。先前的研究已经发现了一些关于圆周运动的误解，尤其是关于作用在旋转物体上的力的误解。物理教师常用的圆周运动定律演示是在垂直平面上旋转一个装满水的水桶，进一步解释了为什么当水桶倒置时水没有溢出。关于圆周运动的主要误解之一是存在所谓的离心力：学生错误地认为，当物体沿圆形路径旋转时，会在径向上作用有实际力，将其拉出路径。因此，最常见的天真解释之一是重力mg被圆形轨迹顶部的离心力所补偿，因此水不会溢出。在本研究中，我们决定将问题的背景从通常的物理课堂演示变为马戏表演的相对不寻常的非正式环境，并研究观众在这种情况下关于圆周运动的想法。因此，本研究的目的是研究在马戏团数背景下提供的关于圆周运动现象的杂龄人群的概念，该数字是在该数字之后的焦点小组访谈中表达的。