AP物理C力学模拟卷Free Response Question

2018ap物理c力学大题

2018ap物理c力学大题
2018年AP物理C力学大题主要涉及以下几个方面：
1. 力学基本概念，题目可能涉及牛顿运动定律、摩擦力、弹簧力、重力等基本力学概念。

学生需要理解这些概念并能够运用它们
解决问题。

2. 动量和能量，题目可能涉及动量守恒定律、动能、势能、机
械能守恒等内容。

学生需要能够分析物体的动能和势能变化，并理
解动量守恒的应用。

3. 旋转运动，题目可能涉及刚体的平衡、转动惯量、角动量等
内容。

学生需要理解刚体平衡的条件，能够计算刚体的转动惯量并
应用相关知识解决问题。

4. 振动和波动，题目可能涉及弹簧振子、简谐振动、波速、波
长等内容。

学生需要理解振动的特点、波动的传播规律，并能够运
用相关公式解决问题。

总体来说，2018年AP物理C力学大题涵盖了力学的基本概念、
动量和能量、旋转运动、振动和波动等多个方面的内容。

学生在备考时需要扎实掌握这些知识点，并能够灵活运用到解决实际问题的能力。

希望这些信息能够对你有所帮助。

ap物理c力学 2020

ap物理c力学 2020AP物理C力学是一门高级的物理学课程，主要涵盖了力学的各个方面，包括力、运动、动量、能量、旋转等内容。

本文将对AP物理C 力学的2020年考试内容进行介绍。

在AP物理C力学考试中，学生需要掌握力学的基本概念和原理，并能够运用这些知识解决各种物理问题。

下面将从几个重要的考点进行介绍。

力是物体运动的原因，是物体之间相互作用的结果。

力的大小可通过牛顿第二定律进行计算，即力等于物体的质量乘以其加速度。

在解题过程中，需要注意力的方向和大小，并注意力的合成和分解问题。

运动是物体位置随时间的变化。

在AP物理C力学考试中，常常涉及到直线运动和曲线运动。

直线运动的特点是速度恒定，而曲线运动则需要考虑速度的变化和加速度的存在。

在解决运动问题时，需要运用运动学公式，包括位移、速度和加速度之间的关系。

动量是物体运动状态的描述，是物体质量和速度的乘积。

动量守恒定律是物理学中的重要原理，它指出在一个系统中，如果没有外力作用，系统的总动量将保持不变。

在解决动量问题时，需要运用动量守恒定律，通过计算物体的质量和速度来确定物体的动量。

能量是物体做功的能力，是物体运动状态的描述。

在AP物理C力学考试中，常常涉及到机械能的转化和守恒。

机械能包括动能和势能，动能是由物体的质量和速度决定的，势能则与物体所处的位置有关。

在解决能量问题时，需要考虑能量的转化和守恒关系。

旋转是物体围绕某个轴心旋转的运动。

在AP物理C力学考试中，常常涉及到转动惯量、角速度和角加速度的计算。

在解决旋转问题时，需要考虑力矩和转动惯量的关系，并运用牛顿第二定律和角动量守恒定律进行计算。

除了上述内容，AP物理C力学考试还涉及到弹性碰撞、万有引力、简谐振动等内容。

这些内容都是力学的重要组成部分，对于学生来说是必须掌握的。

AP物理C力学是一门内容广泛、要求严格的物理学课程。

通过学习力学的基本概念和原理，并能够熟练运用这些知识解决各种物理问题，学生可以在考试中取得好成绩。

2017ap物理c力学真题答案

2017ap物理c力学真题答案一、单项选择题【答案】a考点：电磁感应现象与电流的磁效应现象分辨a.我国水资源是有限的，所以水能是不可再生能源b.发光二极管主要就是由超导材料制成的c.试电笔在使用时，试电笔上的任何金属都不要接触，否则会有触电危险d.工业上采用超音波探伤仪能够检查出来金属零件内部的裂纹【答案】 d【解析】我国水资源是有限的，但水能是可再生能源，a选项不正确;发光二极管是由半导体材料制成的，b选项不正确;使用试电笔时不能接触笔尖金属体，必须接触笔尾金属体，这样才能形成通路，c选项不正确;故d选项正确，选填d考点：再生能源辨识;发光二极管材料;试电笔的采用;超声波应用领域。

a.使用红外线传输数字信号b.使用超声波传输数字信号c.采用光纤传输数字信号d.采用电磁波传输数字信号【答案】d一、单项选择题a.电路中的电阻变大，灯泡变亮b.电路中的电阻变大，灯泡变暗c.电路中的电阻变大，灯泡变暗d.电路中的电阻变大，灯泡变暗【答案】c【考点定位】滑动变阻器【答案】a【解析】电流表的正确使用方法是：与被测用电器串联;电流必须从电流表的正极流入，负极流出;所测量的电流不能超过电流表的量程;绝对不允许不经过用电器把电流表直接接在电源两极上;电压表的正确使用方法是：把它并联在用电器两端;必须让电流从正接线柱流入，从负接线柱流出(正接线柱与正极相连，负接线柱与负极相连);被测电压不能超过电压表所选的量程，否则会烧坏电压表. a、此图中是电流表，即串联在电路中，且正负接线柱是正确的，故a正确;b、此图中是电流表，相当于导线，所以此时将电流表并联，会发生短路，故b错误;c、此图中是电压表，应该并联在用电器两端，故c错误;d、此图中的电压表虽然并联在用电器两端，但正负接线柱接反了，故d错误;故选a.【考点定位】电流表的采用;电压表的采用a.电流表接电源b.电压表接电源c.导线接电源d.家用电器接电源【答案】b【考点定位】电路的连接a.l1、l2两端实际电压相同b.l1、l2电阻之比是25:38c.l1、l2的电流之比为25 :38d.通过调节电源电压，能使l1、l2同时正常工作【答案】b【解析】【考点定位】并联电路的特点a.电流表与的示数的比值将减小b.电压表的示数与电流表的示数的比值将增大c.电压表的示数与电流表示数的乘积将增大d.电流表与的示数的比值将减小【答案】a【解析】由电路图知道r1与r2并联，a测量干路部分的电流，当滑动变阻器的滑片p向右移动时，r1接入电路的电阻增加，电路总电阻增加，所以a与a2的示数减小，v与a1的示数不变。

AP Physics C Mechanics Practice Tests

Contents
Directions for Administration ............................................................................................ ii Section I: Multiple-Choice Questions ................................................................................ 1 Section II: Free-Response Questions .............................................................................. 14 Student Answer Sheet for Multiple-Choice Section ...................................................... 22 Multiple-Choice Answer Key........................................................................................... 23 Free-Response Scoring Guidelines.................................................................................. 24
The actual AP Physics C Exams are administered in one session, Mechanics first followed by Electricity and Magnetism. Students taking only one of the exams will have the most realistic experience if both sections are completed in one session. Similarly, students taking both Physics C exams will have the most realistic experience if both exams are completed in one session and a complete morning or afternoon is available to administer them. If a schedule does not permit one time period for administration, it would be acceptable to administer Mechanics on one day and Electricity and Magnetism on a subsequent day, or to further break things up and administer Section I and Section II of each exam on subsequent days.

【AP物理C】【真题】解答题2008力学

AP® Physi‎c s C: Mecha‎n ics2008 Free-Respo‎n se Quest‎i onsThe Colle‎g e Board‎: Conne‎c ting‎Stude‎n ts to Colle‎g e Succe‎s sThe Colle‎g e Board‎is a not-for-profi‎t membe‎r ship‎assoc‎i atio‎n whose‎missi‎o n is to conne‎c t stude‎n ts to colle‎g e succe‎s s andoppor‎t unit‎y. Found‎e d in 1900, the assoc‎i atio‎n is compo‎s ed of more than 5,000 schoo‎l s, colle‎g es, unive‎r siti‎e s, and other‎educa‎t iona‎l organ‎i zati‎o ns. Each year, the Colle‎g e Board‎serve‎s seven‎milli‎o n stude‎n ts and their‎paren‎t s, 23,000 high schoo‎l s, and 3,500 colle‎g es throu‎g h major‎progr‎a ms and servi‎c es in colle‎g e admis‎s ions‎, guida‎n ce, asses‎s ment‎, finan‎c ial aid, enrol‎l ment‎, and teach‎i ng andlearn‎i ng. Among‎its best-known‎progr‎a ms are the SAT®, the PSAT/NMSQT‎®, and the Advan‎c ed Place‎m ent Progr‎a m® (AP®). The Colle‎g e Board‎is commi‎t ted to the princ‎i ples‎of excel‎l ence‎and equit‎y, and that commi‎t ment‎is embod‎i ed in all of its progr‎a ms, servi‎c es, activ‎i ties‎, and conce‎r ns.© 2008 The Colle‎g e Board‎. All right‎s reser‎v ed. Colle‎g e Board‎, Advan‎c ed Place‎m ent Progr‎a m, AP, AP Centr‎a l, SAT, and the acorn‎logo are regis‎t ered‎trade‎m arks‎of the Colle‎g e Board‎. PSAT/NMSQT‎is a regis‎t ered‎trade‎m ark of the Colle‎g e Board‎and Natio‎n al Merit‎Schol‎a rshi‎p Corpo‎r atio‎n.Permi‎s sion‎to use copyr‎i ghte‎d Colle‎g e Board‎mater‎i als may be reque‎s ted onlin‎e at:www.colle‎g eboa‎r /inqui‎r y/cbper‎m it.html.Visit‎the Colle‎g e Board‎on the Web: www.colle‎g eboa‎r .AP Centr‎a l is the offic‎i al onlin‎e home for the AP Progr‎a m: apcen‎t ral.colle‎g eboa‎r .PHYSI ‎C S C: MECHA ‎N ICSSECTI ‎O N IITime -45 minut ‎e s3 Quest ‎i onsDirec ‎t ions ‎: Answe ‎r all three ‎ quest ‎i ons. The sugge ‎s ted time is about ‎ 15 minut ‎e s for answe ‎r ing each of the quest ‎i ons, which ‎ are worth ‎ 15 point ‎s each. The parts ‎ withi ‎n a quest ‎i on may not have equal ‎ weigh ‎t . Show all your work in the pink bookl ‎e t in the space ‎s provi ‎d ed after ‎ each part , NOT in this green ‎ inser ‎t.2008M ‎1. A skier ‎ of mass M is skiin ‎g down a frict ‎i onle ‎s s hill that makes ‎ an angle ‎ θ with the horiz ‎o ntal ‎, as shown ‎ in the diagr ‎a m. The skier ‎ start ‎s from rest at time t = 0 and is subje ‎c t to a veloc ‎i ty-depen ‎d ent drag force ‎ du e to air resis ‎t ance ‎ of the form F = –bv, where ‎ v is the veloc ‎i ty of the skier ‎ and b is a posit ‎i ve const ‎a nt. Expre ‎s s all algeb ‎r aic answe ‎r s in terms ‎ of M, b, θ, and funda ‎m enta ‎l const ‎a nts.(a) On the dot below ‎ that repre ‎s ents ‎ the skier ‎, draw a free -body diagr ‎a m indic ‎a ting ‎ and label ‎i ng all of the force ‎s that act on the skier ‎ while ‎ the skier ‎ desce ‎n ds the hill.(b) Write ‎ a diffe ‎r enti ‎a l equat ‎i on that can be used to solve ‎ for the veloc ‎i ty of the skier ‎ as a funct ‎i on oftime.(c) Deter ‎m ine an expre ‎s sion ‎ for the termi ‎n al veloc ‎i ty v T of the skier ‎.(d) Solve ‎ the diffe ‎r enti ‎a l equat ‎i on in part (b) to deter ‎m ine the veloc ‎i ty of the skier ‎ as a funct ‎i on of time, showi ‎n g all your steps ‎.(e) On the axes below ‎, sketc ‎h a graph ‎ of the accel ‎e rati ‎o n a of the skier ‎ as a funct ‎i on of time t, and indic ‎a te the initi ‎a l value ‎ of a. Take downh ‎i ll as posit ‎i ve.taO2008M‎2. The horiz‎o ntal‎unifo‎r m rod shown‎above‎has lengt‎h 0.60 m and mass 2.0 kg. The left end of the rod is attac‎h ed to a verti‎c al suppo‎r t by a frict‎i onle‎s s hinge‎that allow‎s the rod to swing‎up or down. The right‎end of th e rod is suppo‎r ted by a cord that makes‎an angle‎of 30° with the rod. A sprin‎g scale‎of negli‎g ible‎mass measu‎r es the tensi‎o n in the cord. A 0.50 kg block‎is also attac‎h ed to the right‎end of the rod.(a) On the diagr‎a m below‎, draw and label‎vecto‎r s to repre‎s ent all the force‎s actin‎g on the rod. Show each force‎vecto‎r origi‎n atin‎g at its point‎of appli‎c atio‎n.(b)Calcu‎l ate the readi‎n g on the sprin‎g scale‎.The rotat‎i onal‎inert‎i a of a rod about‎its cente‎r is 1ML2, where‎M is the mass of the rod and L is its lengt‎h.12Calcu‎l ate the rotat‎i onal‎inert‎i a of the rod-block‎syste‎m about‎the hinge‎.(d)If the cord that suppo‎r ts the rod is cut near the end of the rod, calcu‎l ate the initi‎a l angul‎a r accel‎e rati‎o n of th erod-block‎syste‎m about‎the hinge‎.2008M‎3. In an exper‎i ment‎to deter‎m ine the sprin‎g const‎a n t of an elast‎i c cord of lengt‎h 0.60 m, a stude‎n t hangs‎the cord from a rod as repre‎s ente‎d above‎and then attac‎h es a varie‎t y of weigh‎t s to the cord. For each weigh‎t, the stude‎n t allow‎s the weigh‎t to hang in equil‎i briu‎m and then measu‎r es the entir‎e lengt‎h of the cord. The data are recor‎d ed in the table‎below‎:(a)Use the data to plot a graph‎of weigh‎t versu‎s lengt‎h on the axes below‎. Sketc‎h a best-fit strai‎g ht line throu‎g hthe data.(b) Use the best-fit line you sketc‎h ed in part (a) to deter‎m ine an exper‎i ment‎a l value‎for the sprin‎g const‎a nt k ofthe cord.The stude‎n t now attac‎h es an objec‎t of unkno‎w n mass m to the cord and holds‎the objec‎t adjac‎e nt to the point‎at which‎the top of the cord is tied to the rod, as repre‎s ente‎d above‎. When the objec‎t is relea‎s ed from rest, it falls‎1.5 m befor‎e stopp‎i ng and turni‎n g aroun‎d. Assum‎e that air resis‎t ance‎is negli‎g ible‎.(c)Calcu‎l ate the value‎of the unkno‎w n mass m of the objec‎t.(d)i. Calcu‎l ate how far down the objec‎t has falle‎n at the momen‎t it attai‎n s its maxim‎u m speed‎.ii.Expla‎i n why this is the point‎at which‎the objec‎t has its maxim‎u m speed‎.iii.Calcu‎l ate the maxim‎u m speed‎of the objec‎t.。

【AP物理C】【真题】解答题 C2000

【AP物理C】【真题】解答题 C2000AP? Physics C2000 Free response QuestionsThe materials included in these files are intended for use by AP teachers for course and exam preparation in the classroom; permission for any other use must be sought from the Advanced Placement Program?. Teachers may reproduce them, in whole or in part, in limited quantities, for face-to-face teaching purposes but may not mass distribute the materials, electronically or otherwise. These materials and any copies made of them may not be resold, and the copyright notices must be retained as they appear here. This permission does not apply to any third-party copyrights contained herein.These materials were produced by Educational Testing Service? (ETS?), which develops and administers the examinations of the Advanced Placement Program for the College Board. The College Board and Educational Testing Service (ETS) are dedicated to the principle of equal opportunity, and theirprograms, services, and employment policies are guided by that principle.The College Board is a national nonprofit membership association dedicated to preparing, inspiring, and connecting students to college and opportunity. Founded in 1900, the association is composed of more than 4,200 schools, colleges, universities, and other educational organizations. Each year, the College Board serves over three million students and their parents, 22,000 high schools, and 3,500 colleges, through major programs and services in college admission, guidance, assessment, financial aid, enrollment, and teaching and learning. Among its best-known programs are the SAT?, thePSAT/NMSQT?, and the Advanced Placement Program? (AP?). The College Board is committed to the principles of equity andexcellence, and that commitment is embodied in all of its programs, services, activities, and concerns.APIEL is a trademark owned by the College Entrance Examination Board. PSAT/NMSQT is a registered trademark jointly owned by the College Entrance Examination Board and the National Merit Scholarship Corporation. Educational Testing Service and ETS are registered trademarks of Educational Testing Service.Copyright ? 2000 by College Entrance Examination Board. All rights reserved.College Board, Advanced Placement Program, AP, SAT, and the acorn logo are registered trademarks of the College Entrance Examination Board.(2000 M1) You are conducting an experiment to measure the acceleration due to gravity gu at an unknown location. In the measurement apparatus, a simple pendulum swings past a photogate located at the pendulum's lowest point, which records the time t10 for the pendulum to undergo 10 full oscillations. The pendulum consists of a sphere of mass m at the end of a string and has alength l. There are four versions of this apparatus, each with a different length. All four are at the unknown location, and the data shown below are sent to you during the experiment.t10 T T2 ? (s) (s) (s2) (cm) 12 7.62 18 21 32 8.89 10.09 12.08 a. For each pendulum, calculate the period T and the square of the period. Use a reasonable number of significant figures. Enter these results in the table above.b. On the axes below, plot the square of the period versus the lengthof the pendulum. Draw a best-fit straight linefor this data. c. Assuming that each pendulum undergoes small amplitude oscillations, from your fit determine the experimental value gexp of the acceleration due to gravity at this unknown location. Justify your answer.d. If the measurement apparatus allows a determination of gexp that is accurate to within 4%, is your experimentalvalue in agreement with the value 9.80 m/s2 ? Justify your answer.e. Someone informs you that the experimental apparatus is in fact near Earth's surface, but that the experiment hasbeen conducted inside an elevator with a constant acceleration a. Assuming that your experimental value g is exact, determine the magnitude and direction of the elevator's acceleration.Copyright ? 2000 by College Entrance Examination Board. All rights reserved.College Board, Advanced Placement Program, AP, SAT, and the acorn logo are registered trademarks of the College Entrance Examination Board.2000M2. A rubber ball of mass m is dropped from a cliff. As the ball falls, it is subject to air drag (a resistive force caused by the air). The drag force on the ball has magnitude bv2, where b is a constant drag coefficient and v is the instantaneous speed of the ball. The dragcoefficient b is directly proportional to the cross-sectional area of the ball and the density of the air and does not depend on the mass of the ball. As the ball falls, its speed approaches a constant value called the terminal speed.a. On the figure below, draw and label all the forces on the ball at some instant before it reaches terminal speed.b. State whether the magnitude of the acceleration of the ball of mass m increases, decreases, or remains the sameas the ball approaches terminal speed. Explain.c. Write, but do NOT solve, a differential equation for the instantaneous speed v of the ball in terms of time t, thegiven quantities, and fundamental constants.d. Determine the terminal speed vt in terms of the given quantities and fundamental constants.e. Determine the energy dissipated by the drag force during the fall if the ball is released at height h and reachesits terminal speed before hitting the ground, in terms of the given quantities and fundamental constants.2000M3. A pulley of radius R1 and rotational inertia I1 is mounted on an axle with negligible friction. A light cord passing over the pulley has two blocks of mass m attached to either end, as shown above. Assume that the cord does not slip on the pulley. Determine the answers to parts (a) and (b) in terms of m, R1, I1, and fundamental constants. a. Determine the tension T in the cord.b. One block is now removed from the right and hung on the left. When the system is released from rest, the threeblocks on the left accelerate downward with an acceleration g/3 . Determine the following. i. The tension T3 in the section of cord supporting the three blocks on the left ii. The tension Tl in the section of cord supporting the single block on the right iii. The rotational inertia I1 of the pulleyCopyright ? 2000 by College Entrance Examination Board. All rights reserved.College Board, Advanced Placement Program, AP, SAT, and the acorn logo are registered trademarks of the College Entrance Examination Board.c. The blocks are now removed and the cord is tied into a loop, whichis passed around the original pulley and asecond pulley of radius 2R1 and rotational inertia 16I1. The axis of the original pulley is attached to a motor that rotates it at angular speed ?1, which in turn causes the larger pulley to rotate. The loop does not slip on the pulleys. Determine the following in terms of I1, RI, and ?1. i. The angular speed ?2 of the larger pulleyii. The angular momentum L2 of the larger pulley iii. The total kinetic energy of the system2000E1. Lightbulbs A, B, and C are connected in the circuit shown above.a. List the bulbs in order of their brightness, from brightest to least bright. If any bulbs have the same brightness,state which ones. Justify your answer.Now a switch S and a 5.0 mH inductor are added to the circuit; as shown above. The switch is closed at time t = 0.b. Determine the currents IA, IB, and IC for the following times. i. Immediately after the switch is closed ii. A long time after the switch is closedCopyright ? 2000 by College Entrance Examination Board. All rights reserved.College Board, Advanced Placement Program, AP, SAT, and the acorn logo are registered trademarks of the College Entrance Examination Board.c. On the axes below, sketch the magnitude of the potential difference VL across the inductor as a function of time,from immediately after the switch is closed until a long time after the switch is closed.d. Now consider a similar circuit with an uncharged 5.0 ?F capacitor instead of the inductor, as shown above. Theswitch is again closed at time t = 0. On the axes below, sketch the magnitude of the potential difference Vcap across the capacitor as a function of time, from immediately after the switch is closed until a long time after the switch is closed.Copyright ? 2000 by College Entrance Examination Board. All rights reserved.College Board, Advanced Placement Program, AP, SAT, and the acorn logo are registered trademarks of the College Entrance Examination Board.感谢您的阅读，祝您生活愉快。

ap物理c】真题】解答题c2000

【AP物理C】【真题】解答题C2000AP? Physics C2000 Free response QuestionsThe mat erials included in these files are intended for use by AP teachers for course and exam preparation in the classroom; permission for any other use must be sought from the Advanced Placement Program?. Teachers may reproduce them, in whole or in part, in limited quantities, for face-to-face teaching purposes but may not mass distribute the materials, electronically or ot herwise. These mat erials and any copies made of t hem may not be resold, and the copyright notices must be retained as they appear here. This permission does not apply to any third-party copyrights contained herein.These materials were produced by Educational Testing Service? (ETS?), which develops and administers the examinations of the Advanced Placement Program for the College Board. The College Board and Educational Testing Service (ETS) are dedicated to the principle of equal opportunity, and their programs, services, and employment policies are guided by that principle.The College Board is a national nonprofit membershipassociation dedicated to preparing, inspiring, and connecting students to college and opportunity. Founded in 1900, the association iscomposed of more than 4,200 schools, colleges, universities, and other educational organizations. Each year, the College Board serves over three million students and their parents, 22,000 high schools, and 3, 500 colleges, through major programs and services in college admission, guidance, assessment, financial aid, enrollment, and teaching and learning・ Among its best-known programs are the SAT?, the PSAT/NMSQT?, and the Advanced Placement Program? (AP?). The College Board is committed to the principles of equity andexcellence, and that comm it men t is embodied in allof its programs, services, activities, and concerns.API EL is a trademark owned by the College Ent rance Examination Board・ PSAT/NMSQT is a registeted trademark jointly owned by the College Entrance Examination Board and the National Merit Scholarship Corporation. Educational Testing Service and ETS are registered trademarks of Educational Testing Service.Copyright ? 2000 by College Entrance Examination Board.All rights reserved.College Board, Advanced Placement Program, AP, SAT, and the acorn logo are registered trademarks of the College Entrance Examination Board.(2000 Ml) You are conducting an experiment to measure the acceleration due to gravity gu at an unknown location. In the measurement apparatus, a simple pendulum swings past a photogate located at the pendulum^ s lowest point, which records the time tlO for the pendulum to undergo 10 full oscillations. The pendulum consists of a sphere of mass m at the end of a st ring and has a leng th 1. There are four versions of this apparatus, each with a different length. All four are at the unknown location, and the data shown below are sent to you during the experiment.tio T T2 ? (s) (s) (s2) (cm) 12 18 21 32 a. For each pendulum, calculate the period T and the square of the period. Use a reasonable number of signifies nt figures. Enter these results in the table above.b.On the axes below, plot the square of the period versus the length of the pendulum. Draw a best-fit straight linefor this data. c. Assuming that each pendulum undergoessmall amplitude oscillations, from your fit determine the experimental value gexp of the acceleration due to gravity at this unknown location. Justify your answer.d.If the measurement apparatus allows a determination of gexp that is accurate to within 4%, is your experimentalvalue in agreement with the value m/s2 ? Justify your answer.e.Someone informs you that the experimental appara tus is in fac t neat Ear th's surface, but that the experiment hasbeen conducted inside an elevator with a constant acceleration a. Assuming that your experimental value g is exact, determine the magnitude and direction of the elevatoH s acceleration.Copyright ? 2000 by College Entrance Examination Board. All rights reserved.College Board, Advanced Placement Program, AP, SAT, and the acorn logo are registeted trademarks of the College Entrance Examination Board.2000M2. A rubber ball of mass m is dropped from a cliff. As the ball falls, it is subject to air drag (a resistiveforce caused by the air). The drag force on the ball has magnitude bv2, where b is a constant drag coefficient and v is the instantaneous speed of the ball. The drag coeff icie nt b is direc tly proportional to the cross-sectional area of the ball and the density of the air and does not depend on the mass of the ball. As the ball falls, its speed approaches a constant value called the terminal speed.a.On the figure below, draw and label all the forces on the ball at some instant before it reaches terminal speed.b.State whether the magnitude of the acceleration of the ball of mass m increases, decreases, or remains the sameas the ball approaches terminal speed. Explain.c.Write, but do NOT solve, a differential equation for the instantaneous speed v of the ball in terms of time t, thegiven quantities, and fundamentai constants.d.Det ermine the terminal speed vt in t erms of the given quantities and fundamental constants.e.Determine the energy dissipated by the drag force during the fall if the ball is released at height h and reachesits terminal speed before hitting the ground, in terms of the given quantities and fundamental constants.2000M3・ A pulley of radius R1 and rotational inertiaII is mounted on an axle with negligible friction. A light cord passing over the pulley has two blocks of mass m attached to either end, as shown above. Assume that the cord does not slip on the pulley. Det ermine the answers to parts (a) and (b) in t erms of m, Rl, II, and fundamental constants, a. Determine the tension T in the cord.b.One block is now removed from the right and hung on the left・ When the system is released from rest, the threeblocks on the left accelerate downward with an accelera tion g/3 • Det ermine the following, i. The tension T3 in the section of cord supporting the three blocks on the left ii. The tension T1 in the section of cord supporting the single block on the right iii. The rotational inertia II of the pulleyCopyright ? 2000 by College Entrance Examination Board. All rights reserved.College Board, Advanced Placement Program, AP, SAT, and the acorn logo are registered trademarks of the CollegeEntrance Examination Board.c.The blocks are now removed and the cord is tied into a loop, which is passed around the original pulley and asecond pulley of radius 2R1 and rotational inertia 1611. The axis of the original pulley is attached to a motor that rotates it at angular speed ?1, which in turn causes the larger pulley to rotate. The loop does not slip on the pulleys. Det ermine the following in terms of II, RI, and ?1. i. The angular speed ?2 of the larger pulleyii. The angular momentum L2 of the larger pulley iii. The totai kinetic energy of the system2000E1. Lightbulbs A, B, and C are connected in the circuit shown above.a.List the bulbs in order of t heir brigh tn ess, from brightest to least bright・ If any bulbs have the same brightness,state which ones. Justify your answer.Now a switch S and a mH indue tor are added to the circuit; as shown above. The switch is closed at time t二0・b.Det ermine the curre nts IA, IB, and IC for the following times. i. Immediately after the switch is closedii. A long time after the switch is closedCopyright ? 2000 by College Entrance Examination Board. All rights reserved.College Board, Advanced Placement Program, AP, SAT, and the acorn logo are registered trademarks of the College Entrance Examination Board.c.On the axes below, sketch the magnitude of the potential difference VL across the inductor as a function of time,from immediately after the switch is closed untila long time after the switch is closed.d.Now consider a similar circuit with an uncharged ?F capacitor instead of the induetor, as shown above. Theswitch is again closed at time t 二0・ On the axes below, sketch the magnitude of the potential difference Vcap across the capacitor as a function of time, from immediately after the switch is closed until a long time after the switch is closed.Copyright ? 2000 by College Entrance Examination Board. All rights reserved.College Board, Advanced Placement Program, AP, SAT, and the acorn logo are registered trademarks of the College Entrance Examination Board.2000E2・Three particles, A, B, and C, have equal positive charges Q and are held in place at the vertices of anequilater&l triangle with sides of length 1, as shown in the figures below. The dot ted lines represe nt the bisec tors for each side. The base of the t riangle lies on the x-axis, and the altitude of the triangle lies on the y-axis.a.i.Point Pl, the intersection of the three bisec to rs, loca tes the geometric center of the triangle and is one pointwhere the electrie field is zero. On Figure 1 above, draw the elec trie field vec tors EA, EB, and EC at P, due to each of the three charges. Be sure your arrows are drawn to reflect the relative magnitude of the fields・ii.Another poi nt where the elec trie field is zero ispoint P2 at (0, y2). On Figure 2 above, draw electrie field vectors EA, EB, and EC at P2 due to each of the three point charges. Indicate below whether the magnitude of each of these vectors is greater than, less than, or the same as for point Pl.EA EB EC Greater than at Pl Less than at Pl The same as at Pl b. Explain why the x-component of the total electric field is zero at any point on the y-axis.c.Write a general expression for the electrie potential V at any point on the y-axis inside the trianglein terms of Q,1, and y.d.Describe how the answer to part (c) could be used to determine the y-coordinates of points Pl and P2 at whichthe electric field is zero. (You do not need toactually determine these coordinates.)Copyright ? 2000 by College Entrance Examination Board. All rights reserved.College Board, Advanced Placement Program, AP, SAT, and the acorn logo are registered trademarks of the College Entrance Examination Board.2000E3. A capacitor consists of two conducting, coaxial, cylindrical shells of radius a and b, respec ti vely, and leng th L » b. The space bet ween the cylinders is filled with oil that has a dielectric constant K .Initially bothcylinders are uncharged, but then a battery is used to charge the capacitor, leaving a charge +Q on the inner cylinder and -Q on the outer cylinder, as shown above. Let r be the radial distance from the axis of the capacitor.ing Gauss，s 1aw, determine the electrie field midway along the length of the cylinder for the following valuesof r, in t erms of the given qua ntities and fundamental constants. Assume end effects are negligible. i.a b. Determine the following in terms of the givenquantities and fundamentai constants.i. The potential difference across the capacitor ii. The capacitance of this capacitorc.Now the capacitot is discharged and the oil is drained from it. As shown above, a battery of emf ? is connectedto opposite ends of the inner cylinder and a battery of emf 3? is connected to opposite ends of the outer cylinder. Each cylinder has resistance R. Assume that end effects and the contributions to the magnetic field from the wires are negligible. Using Ampere" s law, determine the magnitude Bof the magnetic field midway along the length of the cylinders due to the current in the cylinders for the following values of r. i. a Copyrigh t ? 2000 by College Ent rance Examina tion Board. All rights reserved.College Board, Advanced Placement Program, AP, SAT, and the acorn logo are registered trademarks of the College Entrance Examination Board.AP? Physics C2000 Free response QuestionsThe mat erials included in these files are intended for use by AP teachers for course and exam preparation in the classroom; permission for any other use must be sought from the Advanced Placement Program?. Teachers may reproduce them, in whole or in part, in limited quantities, for face-to-face teaching purposes but may not mass distribute the materials,electronically or otherwise. These mat erials and any copies made of t hem may not be resold, and the copyright notices must be retained as they appear here. This permission does not apply to any third-party copyrights contained herein.These materials were produced by Educational Testing Service? (ETS?), which develops and administers the examinations of the Advanced Placement Program for the College Board. The College Board and Education&l Testing Service (ETS) are dedicated to the principle of equal opportunity, and theirprograms, services, and employment policies are guided by that principle.The College Board is a national nonprofit membership association dedicated to preparing, inspiring, and connecting students to college and opportunity. Founded in 1900, the association iscomposed of more than 4,200 schools, colleges, universities, and other educational organizations. Each year, the College Board serves over three million students and their parents，22,000 high schools, and 3, 500 colleges, through major programs and services in college admission, guidance, assessment, financial aid, enrollment, and teaching andlearning・ Among its best-known programs are the SAT?, the PSAT/NMSQT?, and the Advanced Placement Program? (AP?). The College Board is committed to the principles of equity andexcellence, and that commitment is embodied in all of its programs, services, activities, and concerns.API EL is a trademark owned by the College Ent rance Examination Board・PSAT/NMSQT is a registeted trademark jointly owned by the College Entrance Examination Board and the National Merit Scholarship Corporation. Educational Testing Service and ETS are registered trademarks of Educational Testing Service.Copyright ? 2000 by College Entrance Examination Board. All rights reserved.College Board, Advanced Placement Program, AP, SAT, and the acorn logo are registered trademarks of the College Entrance Examination Board.(2000 Ml) You are conducting an experiment to measure the acceleration due to gravity gu at an unknown location. In the measurement apparatus, a simple pendulum swings past a photogate located at the pendulum^ s lowest point, which records the time tlO for the pendulum to undergo 10 fulloscillations. The pendulum consists of a sphere of mass m at the end of a st ring and has a length 1. There are four versions of this apparatus, each with a different length. All four are at the unknown location, and the data shown below are sent to you during the experiment.tio T T2 ? (s) (s) (s2) (cm) 12 18 21 32 a. For each pendulum, calculate the period T and the square of the period. Use a reasonable number of significant figures. Enter these results in the table above.b.On the axes below, plot the square of the period versus the length of the pendulum. Draw a best-fit straight linefor this data. c. Assuming that each pendulum undergoes small amplitude oscillations, from your fit determine the experimentai value gexp of the acceleration due to gravity at this unknown location. Justify your answer.d.If the measurement apparatus allows a determination of gexp that is accurate to within 4%, is your experimentalvalue in agreement with the value m/s2 ? Justify your answer.e.S omeone informs you that the experimental apparatus isin fact near Earth^ s surface, but that the experiment has been conducted inside an elevator with a constant acceleration a. Assuming that your experimentai value g is exact, determine the magnitude and direction of the elevatoH s acceleration.Copyright ? 2000 by College Entrance Examination Board. All rights reserved.College Board, Advanced Placement Program, AP, SAT, and the acorn logo are registered trademarks of the College Entrance Examination Board.2000M2. A rubber ball of mass m is dropped from a cliff. As the ball falls, it is subject to air drag (a resistive force caused by the air). The drag force on the ball has magnitude bv2, where b is a const&nt drag coefficient and v is the instantaneous speed of the ball. The drag coefficient b is directly proportional to the cross-sectional area of the ball and the density of the air and does not depend on the mass of the ball. As the ball falls, its speed approaches a constant value called the terminal speed.a.On the figure below, draw and label all the forces on the ball at some inst&nt before it reaches terminal speed.b.State whether the magnitude of theacceleration of the ball of mass m increases, decreases, or remains the sameas the ball approaches terminal speed. Explain.c.Write, but do NOT solve, a differential equation for the instantaneous speed v of the ball in terms of time t, thegiven quantities, and fundamentai constants.d・Determine the terminal speed vt in terms ofthe given quantities and fundamental constants.e. Determine the energy dissipated by the drag force during the fall if the ball is released at height h and reachesits terminal speed before hitting the ground, in terms of the given quantities and fundamental constants.2000M3・ A pulley of radius R1 and rotational inertiaII is mounted on an axle with negligible friction. A light cord passing over the pulley has two blocks of mass m attached to either end, as shown above. Assume that the cord does not slip on the pulley.Determine the answers to parts (a) and (b) in terms of m, Rl, II, and fundamental constants. a. Determine the tension T in the cord.b.One block is now removed from the right and hung on the left・ When the system is released from rest, the threeblocks on the left accelerate downward with an accelera tion g/3 • Det ermine the followin g, i. The tension T3 in the section of cord supporting the three blocks on the left ii. The tension T1 in the section of cord supporting the single block on the right iii. The rotation&l inertia II of the pulleyCopyright ? 2000 by College Entrance Examination Board. All rights reserved.College Board, Advanced Placement Program, AP, SAT, and the acorn logo are registered trademarks of the College Entrance Examination Board.c.The blocks are now removed and the cord is tied into a loop, which is passed around the original pulley and asecond pulley of radius 2R1 and rotational inertia 1611. The axis of the original pulley is attached to a motor that rotates it at angular speed ?1, which in turn causes the larger pulley to rotate. The loop does not slip on the pulleys.Det ermine the following in terms of II, RI, and ?1. i. The angular speed ?2 of the larger pulleyii. The angular momentum L2 of the larger pulley iii. The total kinetic energy of the system2000E1. Lightbulbs A, B, and C are connected in the circuit shown above.a.List the bulbs in order of t heir brigh tn ess, from brightest to least bright. If any bulbs have the same brightness,state which ones. Justify your answer.Now a switch S and a mH indue tor are added to the circuit; as shown above. The switch is closed at time t 二0.b.Det ermine the curre nts IA, IB, and IC for the following times. i. Immediately after the switch is closed ii. A long time after the switch is closedCopyright ? 2000 by College Entrance Examination Board. All rights reserved.College Board, Advanced Placement Program, AP, SAT, and the acorn logo are registered trademarks of the College Entrance Examination Board.c.On the axes below, sketch the magnitude of thepotenti&l difference VL across the inductor as a function of time,from immediately after the switch is closed unt订a long time after the switch is closed.d.Now consider a similar circuit with an uncharged ?F capacitor instead of the inductor, as shown above. Theswitch is again closed at time t = 0. On the axes below, sketch the magnitude of the potential difference Vcap across the capacitor as a function of time, from immediately after the switch is closed until a long time after the switch is closed.Copyright ? 2000 by College Entrance Examination Board. All rights reserved.College Board, Advanced Placement Program, AP, SAT,and the acorn logo are registered trademarks of theCollege Entrance Examination Board.。

AP物理C力学模拟卷MultipleChoiceQuestions

AP物理C⼒学模拟卷MultipleChoiceQuestionsMultiple Choice QuestionsTime: 45 minutes. You may refer to the Constants sheet. However, you may not use the Equations sheet, and you may not use a calculator on this portion of the exam.1. A cannon is mounted on a truck that moves forward at a speed of 5m/s. The operator wants to launch a ball from a cannon so the ball goes as far as possible before hitting the level surface. The muzzle velocity of the cannon is 50 m/s. What angle from the horizontal should the operator point the cannon?A.5°B.41°C.45°D.49°E.85°2. A car moving with speed v reaches the foot of an incline of angleθ. The car coasts up the incline without using the engine.Neglecting friction and air resistance, which of the following is correct about the magnitude of the car's horizontal acceleration aand vertical acceleration a y?xA.a x = 0; a y < gB.a x = 0; a y = gC.a x < g ; a y < gD.a x < g ; a y = gE.a x < g ; a y > g3. A bicycle slows down with an acceleration whose magnitude increaseslinearly with time. Which of the following velocity–time graphs could represent the motion of the bicycle?4. A cart is sliding down a low friction incline. A device on the cartlaunches a ball, forcing the ball perpendicular to the incline, as shown above. Air resistance is negligible. Where will the ball land relative to the cart, and why?A.The ball will land in front of the cart, because the ball'sacceleration component parallel to the plane is greater thanthe cart's acceleration component parallel to the plane.B.The ball will land in front of the cart, because the ball hasa greater magnitude of acceleration than the cart.C.The ball will land in the cart, because both the ball and thecart have the same component of acceleration parallel to theplane.D.The ball will land in the cart, because both the ball and thecart have the same magnitude of acceleration.E.The ball will land behind the cart, because the ball slowsdown in the horizontal direction after it leaves the cart.5.The quantity "jerk," j, is defined as the time derivative of anobject's acceleration,What is the physical meaning of the area under a graph of jerk vs.time?A.The area represents the object's acceleration.B.The area represents the object's change in acceleration.C.The area represents the object's change in velocity.D.The area represents the object's velocity.E.The area represents the object's change in position.6. A particle moves along the x-axis with a position given by theequation x(t) = 5 + 3t, where x is in meters, and t is in seconds.The positive direction is east. Which of the following statements about the particle is FALSE.0.The particle is east of the origin at t = 0.1.The particle is at rest at t = 0.2.The particle's velocity is constant.3.The particle's acceleration is constant.4.The particle will never be west of position x = 0.7. A mass hangs from two ropes at unequal angles, as shown above. Whichof the following makes correct comparisons of the horizontal and vertical components of the tension in each rope?8.The force of air resistance F on a mass is found to obey the equationF = bv2, where v is the speed of the mass, for the range of speedsinvestigated in an experiment. A graph of F N vs. v2 is shown above.What is the value of b?.0.83 kg/mA. 1.7 kg/mB. 3.0 kg/mC. 5.0 kg/mD. 1.0 kg/mE.zero9. A box sits on an inclined plane without sliding. As the angle ofthe plane (measured from the horizontal) increases, the normal force.increases linearlyA.decreases linearlyB.does not changeC.decreases nonlinearlyD.increases nonlinearly10.Which of the following conditions are necessary for an object tobe in static equilibrium?.The vector sum of all torques on the object must equal zero.I.The vector sum of all forces on the object must equal zero.II.The sum of the object's potential and kinetic energies must be zero.C.I onlyD.II onlyE.III onlyF.I and II onlyG.I, II, and III11.A student pushes a big 16-kg box across the floor at constant speed.He pushes with a for ce of 50 N angled 35° from the horizontal, as shown in the diagram above. If the student pulls rather than pushes the box at the same angle, while maintaining a constant speed, what will happen to the force of friction?.It must increase.A.It must decrease.B.It must remain the same.C.It will increase only if the speed is greater than 3.1 m/s.D.It will increase only if the speed is less than 3.1 m/s.12.Consider a system consisting only of the Earth and a bowling ball,which moves upward in a parabola above Earth's surface. The downward force of Earth's gravity on the ball, and the upward force of the ball's gravity on the Earth, form a Newton's third law force pair.Which of the following statements about the ball is correct?.The ball must be in equilibrium since the upward forces must cancel downward forces.A.The ball accelerates toward the Earth because the force ofgravity on the ball is greater than the force of the ball onthe Earth.B.The ball accelerates toward the Earth because the force ofgravity on the ball is the only force acting on the ball.C.The ball accelerates away from Earth because the forcecausing the ball to move upward is greater than the force ofgravity on the ball.D.The ball accelerates away from Earth because the forcecausing the ball to move upward plus the force of the ballon the Earth are together greater than the force of gravityon the ball.13.A mass m is attached to a mass 3m by a rigid bar of negligible massand length L. Initially, the smaller mass is located directly above the larger mass, as shown above. How much work is necessary to flip the rod 180° so that the lar ger mass is directly above the smaller mass?.4mgLA.2mgLB.mgLC.4pmgLD.2pmgL14.A ball rolls horizontally with speed v off of a table a height habove the ground. Just before the ball hits the ground, what is its speed?.A.B.C.vD.15.A pendulum is launched into simple harmonic motion in two differentways, as shown above, from a point that is a height h above its lowest point. During both launches, the bob is given an initial speed of3.0 m/s. On the first launch, the initial velocity of the bob isdirected upward along the pendulum's path, and on the second launch it is directed downward along the pendulum's path. Which launch will cause the pendulum to swing with the larger amplitude?.the first launchA.the second launchB.Both launches produce the same amplitude.C.The answer depends on the initial height h.D.The answer depends on the length of the supporting rope.16.The mass M is moving to the right with velocity v0 at position x= x0. Neglect friction. The spring has force constant k. What is the total mechanical energy of the block at this position?17.A sphere, a cube, and a cylinder, all of equal mass, are releasedfrom rest from the top of a short incline. The surface of the incline is extremely slick, so much so that the objects do not rotate when released, but rather slide with negligible friction. Which reaches the base of the incline first?.the sphereA.the cubeB.the cylinderC.All reach the base at the same time.D.The answer depends on the relative sizes of the objects.18.Block B is at rest on a smooth tabletop. It is attached to a longspring, which is in turn anchored to the wall. Block A slides toward and collides with block B. Consider two possible collisions: Collision I: Block A bounces back off of block B.Collision II: Block A sticks to block B.Which of the following is correct about the speed of block Bimmediately after the collision?.It is faster in case II than in case I ONLY if block B is heavier.A.It is faster in case I than in case II ONLY if block B isheavier.B.It is faster in case II than in case I regardless of the massof each block.C.It is faster in case I than in case II regardless of the massof each block.D.It is the same in either case regardless of the mass of eachblock.19.A 0.30-kg bird is flying from right to left at 30 m/s. The birdcollides with and sticks to a 0.50-kg ball which is moving straight up with speed 6.0 m/s. What is the magnitude of the momentum of the ball/bird combination immediately after collision?.12.0 N?sA.9.5 N?sB.9.0 N?sC. 6.0 N?sD. 3.0 N?s20.The force F on a mass is shown above as a function of time t. Whichof the following methods can be used to determine the impulse experienced by the mass?.multiplying the average force by t maxI.calculating the area under the line on the graphII.taking the integralC.II onlyD.III onlyE.II and III onlyF.I and II onlyG.I, II, and III21.A projectile is launched on level ground in a parabolic path so thatits range would normally be 500 m. When the projectile is at the peak of its flight, the projectile breaks into two pieces of equal mass. One of these pieces falls straight down, with no further horizontal motion. How far away from the launch point does the other piece land?.250 mA.375 mB.500 mC.750 mD.1000 mQuestions 22 and 23A rigid rod of length L and mass M is floating at rest in space farfrom a gravitational field. A small blob of putty of mass m < M is moving to the right, as shown above. The putty hits and sticks to the rod a distance 2L/3 from the top end.22.How will the rod/putty contraption move after the collision?.The contraption will have no translational motion, but will rotate about the rod's center of mass.A.The contraption will have no translational motion, but willrotate about the center of mass of the rod and putty combined.B.The contraption will move to the right and rotate about theposition of the putty.C.The contraption will move to the right and rotate about thecenter of mass of the rod and putty combined.D.The contraption will move to the right and rotate about therod's center of mass.23.What quantities are conserved in this collision?.linear and angular momentum, but not kinetic energyA.linear momentum onlyB.angular momentum onlyC.linear and angular momentum, and linear but not rotationalkinetic energyD.linear and angular momentum, and linear and rotationalkinetic energy24.A car rounds a banked curve of uniform radius. Three forces act onthe car: a friction force between the tires and the road, the normal force from the road, and the weight of the car. Which provides the centripetal force which keeps the car in circular motion?.the friction force aloneA.the normal force aloneB.the weight aloneC. a combination of the normal force and the friction forceD. a combination of the friction force and the weight25.A ball of mass m anchored to a string swings back and forth to amaximum position A, as shown above. Point C is partway back to the vertical position. What is the direction of the mass's acceleration at point C?.along the mass's path toward point BA.toward the anchorB.away from the anchorC.between a line toward the anchor and a line along the mass'spathD.along the mass's path toward point A26.In a carnival ride, people of mass m are whirled in a horizontalcircle by a floorless cylindrical room of radius r, as shown in the diagram above. If the coefficient of friction between the people and the tube surface is µ, what minimum speed is necessary to keep the people from sliding down the walls?Questions 27 and 28The uniform, rigid rod of mass m, length L, and rotational inertiaI shown above is pivoted at its left-hand end. The rod is released from rest from a horizontal position.27.What is the linear acceleration of the rod's center of mass the moment after the rod is released?28.What is the linear speed of the rod's center of mass when the mass passes through a vertical position?29.The 1.0-m-long non-uniform plank, shown above, has weight 1000 N.It is to be supported by two rods, A and B, as shown above. The center of mass of the plank is 30 cm from the right edge. Each support bears half the weight of the plank. If support B is 10 cm from the right-hand edge, how far from the left-hand edge should support A be?.0 cmA.10 cmB.30 cmC.50 cmD.70 cm30.A mass m on a spring oscillates on a horizontal surface with periodT. The total mechanical energy contained in this oscillation is E.Imagine that instead a new mass 4m oscillates on the same springwith the same amplitude. What is the new period and total mechanical energy?31.A mass m is attached to a horizontal spring of spring constant k.The spring oscillates in simple harmonic motion with amplitude A.What is the maximum speed of this simple harmonic oscillator?32.An empty bottle goes up and down on the surface of the ocean, obeyingthe position function x= Acos(t). How much time does this bottle take to travel once from its lowest position to its highestposition?33.The Space Shuttle orbits 300 km above the Earth's surface; theEarth's radius is 6400 km. What is the acceleration due to Earth's gravity experienced by the Space Shuttle?. 4.9 m/s2A.8.9 m/s2B.9.8 m/s2C.0.8 m/s2D.zero34.An artificial satellite orbits Earth just above the atmosphere ina circle with constant speed. A small meteor collides with thesatellite at point P in its orbit, increasing its speed by 1%, but not changing the instantaneous direction of the satellite's velocity. Which of the following describes the satellite's new orbit?.The satellite now orbits in an ellipse, with P as the farthest approach to Earth.A.The satellite now orbits in an ellipse, with P as the closestapproach to Earth.B.The satellite now orbits in a circle of larger radius.C.The satellite now orbits in a circle of smaller radius.D.The satellite cannot maintain an orbit, so it flies off intospace.35.Mercury orbits the sun in about one-fifth of an Earth year. If 1AU is defined as the distance from the Earth to the sun, what is the approximate distance between Mercury and the sun? .(1/25) AUA.(1/9) AUB.(1/5) AUC.(1/3) AUD.(1/2) AU。