## Abstract

In a number of excellent, even recently published, books in Theoretical Mechanics the equations of motion of a folded inextensible string, for example to explain the crack of a whip, are derived using either the energy principle, if a system of one degree of freedom is considered, or Lagrange's equations for conservative systems, if a system of more than one degree of freedom is studied. However, it will be shown in this paper that the resulting equations are incorrect because physically a nonconservative system is given. Hence, both methods mentioned above based on energy conservation must not be used. A correct derivation of the equations of motion is given by means of the linear momentum balance.

Original language | English |
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Pages (from-to) | 960-970 |

Number of pages | 11 |

Journal | ZAMP Zeitschrift für angewandte Mathematik und Physik |

Volume | 46 |

Issue number | 6 |

DOIs | |

Publication status | Published - Nov 1995 |

Externally published | Yes |