The International Physicists' Tournament (IPT) 2019 dealt with 17 challenging problems. In this article, we present experimental as well as theoretical approaches exemplarily to one of these tasks. A ball placed on a hard and at surface can show oscillation movement when being hit by a jet of water from above. To explain the oscillations, a theoretical model is introduced and its predictions are compared to the experimental measurements. Furthermore, the structure of the IPT itself is characterized shortly in this article, as well as the idea of a new and innovative seminar which was set up at Erlangen University to prepare and assist students in taking part in International Physicists' Tournament. Furthermore, the educational relevance of physics tournaments like IPT for physics education at university is discussed in detail.

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由于水射流中球的延迟驱动引起的振荡 - 2019 年国际物理学家锦标赛的一个具有挑战性的问题

2019 年国际物理学家锦标赛 (IPT) 处理了 17 个具有挑战性的问题。在本文中，我们展示了这些任务之一的实验和理论方法。放置在坚硬的表面上的球在被从上方喷射的水流击中时会表现出振荡运动。为了解释振荡，引入了一个理论模型，并将其预测与实验测量值进行比较。此外，本文还简要介绍了 IPT 本身的结构，以及在埃尔兰根大学设立的一个新的创新研讨会的想法，该研讨会旨在准备和帮助学生参加国际物理学家锦标赛。此外，还详细讨论了物理竞赛（如 IPT）对大学物理教育的教育意义。