AP-物理C-力学-2021真题卷1.pdf

2021 AP Physics C:Mechanics Free-Response Questions Set 1 2021 College Board.College Board,Advanced Placement,AP,AP Central,and the acorn logo are registered trademarks of College Board.Visit College Board on the web:collegeboard.org.AP Central is the official online home for the AP Program:apcentral.collegeboard.org.ADVANCED PLACEMENT PHYSICS C TABLE OF INFORMATION CONSTANTS AND CONVERSION FACTORSProton mass,271.6710 kgpm?Neutron mass,271.6710 kgnm?Electron mass,319.1110 kgem?Avogadros number,23106.0210 molN?Universal gas constant,8.31 J(mol K)R?Boltzmanns constant,231.3810J KBk?Electron charge magnitude,191.6010 Ce?1 electron volt,191 eV1.6010 J?Speed of light,3.0010 m sc?8 Universal gravitational constant,?11226.6710 N mkgG?Acceleration due to gravity at Earths surface,29.8 m sg?1 unified atomic mass unit,2721 u1.6610 kg931 MeV c?Plancks constant,?34156.6310 J s4.1410 eV sh?253?1.9910 J m1.2410 eV nmhc?Vacuum permittivity,?122208.8510CN me?Coulombs law constant,?92201 49.010 N mCkpe?Vacuum permeability,70410(T m)Amp?Magnetic constant,?704110(T m)Akmp?1 atmosphere pressure,5251 atm1.010 N m1.010 Pa?UNIT SYMBOLS meter,mkilogram,kgsecond,sampere,Akelvin,Kmole,molhertz,Hznewton,Npascal,Pajoule,Jwatt,Wcoulomb,Cvolt,Vohm,Whenry,Hfarad,Ftesla,Tdegree Celsius,C?electron volt,eV PREFIXES FactorPrefixSymbol910gigaG610megaM310kilok210?centic?310millim610?microm910?nanon1210?picopVALUES OF TRIGONOMETRIC FUNCTIONS FOR COMMON ANGLESq0?30?37?45?53?60?90?sinq0 1 23 5 2 2 4 5 3 21 cosq1 3 24 5 2 2 3 5 1 2 0 tanq03 3 3 414 3 3?The following assumptions are used in this exam.I.The frame of reference of any problem is inertial unless otherwisestated.II.The direction of current is the direction in which positive chargeswould drift.III.The electric potential is zero at an infinite distance from an isolatedpoint charge.IV.All batteries and meters are ideal unless otherwise stated.V.Edge effects for the electric field of a parallel plate capacitor arenegligible unless otherwise stated.ADVANCED PLACEMENT PHYSICS C EQUATIONS MECHANICSa=acceleration E=energy F=force f =frequency h=height I =rotational inertia J=impulse K=kinetic energy k=spring constant?=lengthL=angular momentum m=mass P=power p=momentum r =radius or distance T=period t =time U=potential energy v=velocity or speed W=work done on a system x =position m=coefficient of friction q=angle t =torque w =angular speed a =angular acceleration f=phase angle 0?xxa tx20012?xxxxta t?2202?xxxaxx?0netFFamm?dpFdtD?JF dtp?pmv?m?fNFFD?EWF dr212?Km?dEPdt?PF vDD?gUmg h22w?carrt?rFtta?netII2Ir dmm?2ri icmim xxm?w?rw?LrpI212KIw?0twwa?20012ttwa?D?sFk x?212D?sUkxmaxcos(xxtwf?21Tfpw?2smTkp?2pTgp?122?GGm mFr12GGm mUr?ELECTRICITY AND MAGNETISM A=area B=magnetic field C=capacitance d =distance E=electric field e=emfF=force I =current J =current density L=inductance?=lengthn =number of loops of wire per unit length N=number of charge carriers per unit volume P=power Q=charge q =point charge R=resistance r =radius or distance t =time U=potential or stored energy V=electric potentialv =velocity or speed r=resistivity F=flux k=dielectric constant 21 2014pe?Eq qFr?EFEq?0e?QE dA?xdVEdxD?VE dr014pe?iiiqVr1 2014pe?Eq qUqVrD?QVC0ke?ACdpiiCC?11siiCC?dQIdt?21122CUQ VCVD?DRAr?r?EJ?dINev AD?VIRiisRR?11iipRR?D?PI V?MFqvB?0m?B dI024mp?I drdBr?FI dB?0sBnIm?F?BB dAeF?BdE ddtdILdte?212LULI?ADVANCED PLACEMENT PHYSICS C EQUATIONS GEOMETRY AND TRIGONOMETRY A =area C=circumference V =volume S =surface area b =base h =height=lengthw=width r =radius s =arc lengthq=angleRectangle Abh?Triangle 12Abh?Circle 2Ap?r 2Crp?srq?Rectangular Solid Vw?hCylinder 2Vrp?222Srrpp?Sphere 343Vrp?24Srp?Right Triangle 222abc?sinacq?cosbcq?tanabq?s r qcab90qCALCULUSd fd f dudxdu dx?1ndxnxdx?n?axaxdeaedx?daxdxx1ln?sincos?daxaaxdx?cossin?daxaaxdx11,11nnx dxxnn?1?axaxedxealn?dxxaxa?1cossin?ax dxaxa?1sincos?ax dxaxaVECTOR PRODUCTS cosA BABq?sinABABq?ORNAP Physics C:Mechanics 2021 Free-Response QuestionsBegin your response to QUESTION 1 on this page.PHYSICS C:MECHANICS SECTION II Time45 minutes 3 Questions Directions:Answer all three questions.The suggested time is about 15 minutes for answering each of the questions,which are worth 15 points each.The parts within a question may not have equal weight.Show all your work in this booklet in the spaces provided after each part.1.A 0.50 kg fan cart is placed on a level,horizontal track of negligible friction,as shown.The fan is turned on,and the fan cart is released from rest and moves to the right.The cart travels along the horizontal track and thendown an incline.Motion detector 1 measures the acceleration a of the cart from time t 0 to t 3s.Att 3s,the cart makes a smooth transition to the incline,and motion detector 2 measures the acceleration of thecart after t 3s.The fan exerts the same magnitude of force on the cart during the entire motion.The graphsbelow show a as functions of t.For each motion detector,the positive direction is away from the detector.GO ON TO THE NEXT PAGE.Use a pencil 。