When you pull and unwind a toilet roll, it rolls away from you, whatever angle the force is applied. But what happens when you pull on a spool with a smaller internal diameter than the outside?

中文翻译：

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滚动阀芯—问题

当您拉动并松开卫生纸时，无论以何种角度施加力，卫生纸都会从您身上滚开。但是，当您拉动内径小于外径的线轴时会发生什么？