Çàäà÷à 1.1

Íà ãëàäêîì ãîðèçîíòàëüíîì ñòîëå ëåæèò ïðèçìà ìàññû  ñ óãëîì íàêëîíà , à íà íåé – ïðèçìà ìàññû . Íà ìåíüøóþ ïðèçìó äåéñòâóåò ãîðèçîíòàëüíàÿ ñèëà , ïðè ýòîì îáå ïðèçìû äâèæóòñÿ êàê îäíî öåëîå âäîëü ñòîëà. Îïðåäåëèòü ñèëó òðåíèÿ ìåæäó ïðèçìàìè.

 

Ðåøåíèå.

Çàïèøåì óðàâíåíèå äâèæåíèÿ äëÿ ìàëåíüêîé ïðèçìû

                                 (1)

                                       (2)

                                 (3)

Çàïèøåì óðàâíåíèå âòîðîãî çàêîíà Íüþòîíà äëÿ áîëüøîé ïðèçìû:                                                             (4)

                                                                                  (5)

                                                                                                       (6)

Èç (3) îïðåäåëèì óñêîðåíèå:

                                                                                                 (7)

Ïðèðàâíÿåì (6) è (7):                               (8)

                                                                                                          (9)

 (9) ïîäñòàâèì  èç (2). Ïîëó÷èì: 

               Îòâåò: .