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Date: 30-11-2020
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Date: 14-3-2021
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Date: 29-12-2016
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Uniform Circular Motion
In the case of circular motion we always know that the acceleration is . Thus we always know the right hand side of Newton's second law, namely
The forces that produce circular motion get put into the left hand side.
Example In designing a curved road, engineers consider the speed v of a car and the coeffcient of friction between the car tires and the road. The radius of curvature of the road bend is chosen to be large enough so that the car will be able to derive around smoothly in a part-circle. Work out a formula for the radius of curvature in terms of the speed of the car and the coeffcient of friction.
Solution Force diagrams are shown in Fig. 1.1. The top part of the figure shows that static friction alone keeps the car in circular motion. (The forward motion of the car involves moving kinetic friction, but the sideways motion involves static friction.)
FIGURE 1.1 Car rounding a curve.
In the x direction
We get N from the y direction,
Substituting into the x equation gives
or
This formula tells an engineer how large to make the radius of curvature of the road for a given car speed v (say 5 times the speed limit) and a coeffcient of friction μs.
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دراسة: وقت ممارسة الرياضة مهم لفقدان الوزن
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ما مدى خطورة الاضطراب الجوي أثناء الطيران؟
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في السيرة النبوية قسم الشؤون الفكرية يدعو للاشتراك في مسابقة أفضل قصة قصيرة
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أكثر من عشرة آلاف طالب يشاركون في الدورات القرآنية الصيفية ببغداد
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في قضاء الهندية المجمع العلمي يحيي ولادة الإمام الرضا (عليه السلام) بمحفل قرآني
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بعد إعلانه دعوة المشاركة مجمع العفاف النسوي يشهد إقبالًا واسعًا للمشاركة في معرضه التسويقي
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