推 andy74139 :已收錄至資訊系精華區!! 01/15 20:50
課程名稱︰普通物理甲
課程性質︰系上必修
課程教師︰吳俊輝
開課學院：電資學院
開課系所︰資訊工程系
考試日期（年月日）︰2010/01/15
考試時限（分鐘）：110分鐘
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
考試規則:考試時間10:20am-12:10pm, 中途離開座位時須至助教處簽離,回座位時須
簽到。不可看書,不可交談,不可作弊,不可用計算機,手機一律關機。計算皆須有完整
過程,答案標示清楚。
Exam rules: Exam time is between 10:20-12:10. When leaving the classroom for
bathroom, you need to sign out at the TA, and sign in at return. No open
books, no talking, no cheating, NO calculators, and all mobile phones should
be turn OFF. All answers should include a complete procedure that leads to
the answer. Mark the answers clearly.
Q1. (50%)Consider the flight of a beam of particles produced in a nuclear
reactor. These particles have kinetic energies of up to E1. The rest mass of
the particle is m0.
(a)What is the speed of the particle with energy E1?
(b)If the average lifetime of such a particle is T (in the laboratory
reference frame), what is the maximum length L of a beam of such particles
(in a vacuum, in the absence of any interactions between the particles and
other material)? Estimate this maximum range by calculating the length
corresponding to five mean lifetimes.
(c)Draw a diagram to show now the maximum length L varies according to E1.
Indicate especially the cases when m0*c^2 >> E1 and when m0*c^2 << E1.
(也就是畫一個二為取縣圖,縱軸為L,橫軸為E1,並特別標示出m0*c^2 >> E1 及 m0*c^2 <<
E1時的部分).
Q2.(50%) 太空中有一太空船，在地球時間t=0時出發，沿直線路徑以等速率v遠離地球.
地球時間t1時由地球發出一訊號,該訊號在地球時間t2時被太空船接收, 太空船並在地
球時間t3時發出訊號,於地球時間t4時被地球接收。以之t1<t2<t3<t4.回答下列各題
(請務必說清楚,講明白):
(a)再以地球為參考系的Minkowski Diagram 中,畫出以上的所有過程,並標出各事件的
座標點.
(b)在太空船的參考系中,期接收到訊號誌發出訊號的時間間隔為多少?
(c)在太空船的參考系中,期接收到訊號誌發出訊號間所走的距離為多少?
(d)在以太空船為參考系的Minkowski Diagram中,畫出以上的所有過程,並標出各
事件的座標點.
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