Two pendula of length l , suspended from points separated by a horizontal distance a , can be joined in a trapezium configuration by linking the bobs with a light inextensible string of length b < a . Here we introduce this ‘trapezoidal pendulum’ as a charming and novel oscillatory system suitable for introductory physics laboratories. In particular, we show that the time period τ is given by a scale-invariant equation of the form ( τ / τ s ) = P ( a , b , l ), where ##IMG## [http://ej.iop.org/images/0031-9120/55/6/065008/pedaba2a8ieqn1.gif] {$\tau_s(l) = 2\pi\sqrt{l/g}$} (with g gravity), and P ( a , b , l ) is a dimensionless function of a , b , and l . The trapezoidal pendulum exhibits richer behaviour than the canonical simple pendulum, but is nevertheless easy to construct from basic household items, making it an ideal...

中文翻译：

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梯形摆的介绍：适用于远程教学的耦合摆的动力学

悬垂在水平距离为a的点上的两个长度为1的摆锤可以通过将吊钩与长度为b <a的不可伸长的细绳连接而以梯形形式连接。在这里，我们介绍这种“梯形摆”，它是一种引人入胜的新颖振荡系统，适用于物理入门实验室。特别地，我们显示出时间周期τ由形式为（τ/τs）= P（a，b，l）的比例不变方程式给出，其中## IMG ## [http：// ej。 iop.org/images/0031-9120/55/6/065008/pedaba2a8ieqn1.gif] {$ \ tau_s（l）= 2 \ pi \ sqrt {l / g} $}（重力为g），P（a ，b，l）是a，b和l的无量纲函数。梯形摆比标准的简单摆表现出更丰富的行为，但是仍然很容易从基本的家用物品中构造出来，使其成为理想的...