课程名称︰普通物理甲 课程性质︰系上必修 课程教师︰吴俊辉 开课学院：电资学院 开课系所︰资讯工程系 考试日期（年月日）︰2010/01/15 考试时限（分钟）：110分钟 是否需发放奖励金：是 （如未明确表示，则不予发放） 试题 : 考试规则:考试时间10:20am-12:10pm, 中途离开座位时须至助教处签离,回座位时须 签到。不可看书,不可交谈,不可作弊,不可用计算机,手机一律关机。计算皆须有完整 过程,答案标示清楚。 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. (也就是画一个二为取县图,纵轴为L,横轴为E1,并特别标示出m0*c^2 >> E1 及 m0*c^2 << E1时的部分). Q2.(50%) 太空中有一太空船，在地球时间t=0时出发，沿直线路径以等速率v远离地球. 地球时间t1时由地球发出一讯号,该讯号在地球时间t2时被太空船接收, 太空船并在地 球时间t3时发出讯号,於地球时间t4时被地球接收。以之t1<t2<t3<t4.回答下列各题 (请务必说清楚,讲明白): (a)再以地球为参考系的Minkowski Diagram 中,画出以上的所有过程,并标出各事件的 座标点. (b)在太空船的参考系中,期接收到讯号志发出讯号的时间间隔为多少? (c)在太空船的参考系中,期接收到讯号志发出讯号间所走的距离为多少? (d)在以太空船为参考系的Minkowski Diagram中,画出以上的所有过程,并标出各 事件的座标点. --

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