8. ب.1- قمر اصطناعي يتحرك حول كوكب سيار (R)T
يتحرك القمر الاصطناعي في حركة دائرية تحت تأثير قوة الجاذبية فقط (سقوط حر).
نشير إلى القوة الجاذبة نحو المركز بـ Fg.
نرسم مخطط للقوى المؤثرة على الجسم:
نكتب معادلة الحركة الدائرية.
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لذلك ، فإن التعبير عن زمن الدورة كدالة لنصف قطر المدار هو:
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