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## ฟิสิกส์โอลิมปิก วิทยาศาสตร์โอลิมปิก ข้อสอบแข่งขัน ข้อสอบชิงทุน => GRE - Physics => Topic started by: conantee on September 20, 2010, 09:15:34 PM

 Title: GR9277.048 Post by: conantee on September 20, 2010, 09:15:34 PM 48. The magnitude of the force on an object can be determined by measuring both the mass of an object and the magnitude of its aceleration , where . Assume that these measurements are uncorrelated and normally distributed. If the standard deviations of the measurements of the mass and the accelerations are and , respectively, then is (A) (B) (C) (D) (E) Title: Re: GR9277.048 Post by: gons on September 22, 2010, 08:23:33 PM ตอบ (C) จาก จะได้ Title: Re: GR9277.048 Post by: conantee on September 26, 2010, 02:24:34 AM The correct answer is (C) krub. This question is straightforward. No trick as far as I know.The keywords are "uncorrelated" and "normally distributed". The uncertainty is thus related by square relation.That is, , not just 66 of 100 people answer this question correctly.