Физика макротел. Механика макроскопических тел, страница 25

 


           

            Fвнеш                          Fупр

                           -х

                                              -х

                                                                                                                   х

      х

                                                                                       Fупр            Fвнеш

                                                                                    х

Растяжение:

dч=dx