حلول التدريبات العملية الديناميكا لجسمين

8.1. ايجاد التسارع

يتحرك الجسم 1 عموديًا بينما يتحرك الجسم 2 على طول السطح المائل.

نظرًا لأن الجسمين موصولين بخيط مثالي مشدود، فإن تسارعهما متساوي المقدار.

لضمان أن يكون لتسارع كل منهما نفس الإشارة، نحدّد المحاور على النحو التالي:

للجسم 1: نختار المحور Y لأسفل.

بالنسبة للجسم 2: نختار المحور X لأعلى السطح المائل والمحور Y العمودي على السطح لأعلى.

تؤثر قوتان على الجسم 1: قوة الجاذبية W₁ وقوة التوتر T.

نرسم مخططًا للقوى المؤثرة على الجسم 1: 

نكتب معادلة الحركة للجسم 1 بالنسبة لمحور y المختار لأسفل. 

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تؤثر ثلاث قوى على الجسم 2:  قوة الشد T وقوة الجاذبية W₂ والقوة العمودية N₂ .

نحلل القوة تحليل قائم الزاوية  W₂:

في اتجاه المحور Y ، يكون الجسم 2 في حالة سكون. في اتجاه المحور X ، يتحرك الجسم 2 بتسارع.

نكتب معادلات الحركة 2 في كلا الاتجاهين عموديًا على السطح وباتجاه موازيًا له في اتجاه المحور x الذي تم اختياره:

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نجمع معادلتي الحركة  1 و- 2:

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