2021年北京市高考物理试卷（附答案详解）

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12°ᵯc"ER=2^E=»ᦑcKATIJDஹ᪷yc4ᳮQ¢£½¾]^Ḅ°_|h¿ᦑ஺┯J஺ᦑ⌱a᪷0123456ᑮABCBCḄᐵÁᵫiᑖ᪆ABCḄsᓄÄÅ᪷¤¥4ᑣQ¢£+ᵯḄ¦ᔣK᪷_cᐵÁஹᯖὡ456ᵯ·R®ὑḄ°ᵯcK᪷yc4ᳮQ¢£½¾]^Ḅ°_஺⚪Æ⌕ÇὃÉᵯÊᐵËÇÌÍ΢£ḄRyÄÅÏ]ÄÅ᪷012345ᑡ¦¬ÐSÑABCᜧn᪷yc4ᳮஹ_cᐵÁஹᯖὡ45|ÐSᑖ᪆஺8.ூᫀ௃Bூ᪆௃ÒÓ^ᒴB᳛RyÏ]Ö⊝ØÙᚁḄᜳÜ"ÝÒÓÏᑮḄ᥅ß]"/,ᙠ᜜â᪷Ï]Ö⊝6Fj=/+mgsind,iḄ_᳛"P[=+mgsinO)v,ᙠãâ᪷Ï]Ö⊝6F=f,iḄ_᳛"P2=F2"=/U,2ᙠMâ᪷Ï]Ö⊝6ä3=/—mgsåÝiḄ_᳛"P3=F3V=(/-mgsind)v,ᡠ5PT>P?>P3,ᦑBACO┯JKᦑ⌱B஺᪷ØᚁÙᚁÏ]ÄÅᑖ᪆ÒÓḄᱫ\]Ḅᜧn᪷P=Fuᑖ᪆ÒÓḄ_᳛ḄsᓄÄÅ஺i⚪ὃÉ_᳛Ḅçè⚪ḄᐵËÇéÒÓᒴBRyÏ]Ö⊝ᑖ᪆rêÄÅÙᱫ\]Ḅᜧn஺9.ூᫀ௃Cூ᪆௃4᝞ᡠìM@P@ᵯíîḄïð¬CñêMP@ᵯíCᜧnñêᦑA┯JK

13B'M@N@ᑮòᵯ₹Ḅ-.ôñêqõöhê'ª|÷☢Øᵯ÷ñêᦑ8┯JKC᝞ØᡠìMNP@ᵯíîïð¬Cíᜧnñêᐸ+N@P@Ḅ¦ᔣñêᦑCKD'ùᵯíî¦ᔣᵯ÷⌲ûknM@ᵯ÷ᜧhP@ᵯ÷ᵯüýòᵯòᵯ₹ᙠᵯ÷þÿḄᙢᵯᜧᦑᵯᙠᵯᜧMᵯᦑ஺┯ᦑ⌱Coᵯᔣᵯ⌲᪷ᵯ₹ᡠ#ᡂḄᵯ%&ᑖ᪆஺)៉+,-.ᵯ₹/0.ᵯ₹#ᡂḄᵯ%&12ᵯ%&34⚪ᨵ7ᜧ89஺10.ூ;ᫀ௃Dூ>᪆௃>AஹᙊABCDEFᱥHᡠI᥅KLMNᔣOLᡠ1᥅KLᔣPQᔣᢣᔣᙊOᦑA┯BஹᙊABCDEF᪷E,Sᳮ/=/p,ᱥHDEXᙌZᑮ\]^_`ᡠ1E,`ᓄ,b0,᥅KLḄc,b0,ᦑB┯CஹᙊABCDEdᱥHeBCFḄ]^ᔣ4ᒴ]gEᦑC┯LஹᙊABCDEdᱥHeBCFḄ]^ᔣ4ᒴ]gEBCDEhiḄ]^v=ᨬkBCgE]^b0,᪷E,Sᳮ/=/p,lmE,`ᓄ,brncor,ᡠ1᥅KLḄc,bm3r,ᦑDn஺ᦑ⌱D„ᙠᙊABCgEF᪷ᒴ]ᙊᕜgEḄpql1ᑖ᪆᥅KLḄᔣrsE,Sᳮl1tu᥅KLḄc,ᜧᙊABCDEdᵫwឋl1mᱥHgEḄᔣrsE,Sᳮl1tyᱥHᡠI᥅KLḄc,ᜧ஺z⚪{⌕ὃ~ᙊᕜgEḄpq/E,Sᳮ7bᓫ஺14⚓ᐳ22⚓

1411.ூ;ᫀ௃Dூ>᪆௃>Aஹ⊤┐᧳Es⊤ᑁᙌ⌕ᑗᒘᵯEᦑA┯Bஹ⊤┐᧳Es⊤ᑁᙌᵯEᵫᵯᔠᑣᙌᨵᵯᙌ_ILḄᵨᦑB┯CD,¡d#ᡂᔠZ⊤┐᧳Es⊤ᑁᙌᵯᙌIᑮLᵨ¢£ᙌḄDE⊤┐᧳E¤ᦑC┯஺n஺ᦑ⌱஺஺_/¡⊤┐᧳Es⊤ᑁᙌ¥⌕ᵯE¡d,§⌕ᵯᙌIᑮLḄ¢£ᵨ⊤┐¨©ḄBªᩭ஺>;¬⚪⌕m⍝ᙠg®ᵯ⊤.r¯¥ᵨ°ᵯ⊤Ḅ±²³´µᩭ,¶·gᵨᵯ¢¸Ḅᵨ¹ᢣ┐_º»ᜧ¼^Ḅ½D஺12.ூ;ᫀ௃Aூ>᪆௃>ᑭᵨ¿ÀSᑣÁyÂÃÄÅḄÆÇᐻLḄᔣᵫzᑨÊyᙊOḄᡠᙠÄÅ᪷ËÌᐵÎlucos300=pᡠ1Ï=ÐᡈᙠᵫÆÇᐻLMNᔣOLᓽ=-7=Ðᓄu8ᖴ,2nmT=--oqBᵫzlmÓᵯÔᙠḄgEÕÖ·×XnSØltḄᦑAnÙbv/B¥mᡠ1ÓᵯÔᙠḄgEiÚÛÜnSᦑBCO┯஺ᦑ⌱A஺ᙠᵫÆÇᐻLMNᔣOLᑭᵨ¿ÀSᑣᑨÊyÆÝLḄᔣᑭᵨÆÇᐻLḄÞßyᙊOᡠᙠÄź᪷ËÌᐵÎ/ᔣOLàát>஺

15)៉¿ÀSᑣl᪷ÂÃ]^ḄᔣᑨÊyᙊOḄᡠᙠÄÅ⌕ᗐ〉ᵨäᔠᐵÎnSPQrḄᜧὶæàát>ᓽl஺13.ூ;ᫀ௃Aூ>᪆௃>çèéḄê^Îᦪb¡ìᳫî,b஻?ªñòᢞìᳫ☟Cᢣ┐Äõö40C/M÷^ᜐᑣmg=/c(40-20)xIO-2=0.2kAஹ30cM÷^᪷ùúûSqᨵ:k(30-20)x10-2-mg=ma,>ua=-0.5g,ᦑAnBஹ4(km÷^ìᳫ☟Cᦑa=0,ᦑB┯Cஹ50cm÷^᪷ùúûSqᨵfc(50-20)xIO-2-mg=ma,>ua=0.5g,ᦑC┯Dஹ᪷ùúûSqᨵ40—20)x10-2—=ýþlu஺=ÿ
:—g,ᑣᔜḄᙳᒴḄᦑ஺┯ᦑ⌱:Aoᱥᙠ40஺"ᜐ⊝᝱᪷#ᐳ%&⊝'()*Ḅ)&+&Ḅᐵ-.ᱥᙠ/01᪷#2&ᑖ᪆ᑭᵨ789:;ᓽ='(஺>⚪@⌕ὃCD789:;ᐵEᢕGᱥᙠ/012ᑮḄ)*Ḅ)&ᜧJᓽ=KLᵨMN:;஺14.ூRᫀ௃DூU᪆௃UVAஹXYᐝḄᵯ\ᙠ]^_`a1bcᙊef⍝ᑗijkᵯ]lmn“0plm”஺ᜐrj᝱Ḅs\/t:Ḅbujᙢᔣxyz{Ḅx|}~kᐝ\ns\jᐝḄᳮὅjᐝḄᳮ/0ᦑA┯Bஹ᝱Ḅs\ᵯ◤⌕Ḅxy13.6W,ᓫᵯ\ᙌlmḄxy104ei/>i3.6eU,ᡠᵨ0plmᐝ᯿ms\xs\ᵯᦑ8┯Cஹ0plmᐝᐹᨵᐝ(᜜ᑮXᐝ¡10-567n¢£¤ᑖ\Ḅi10-8=ᵨ0plmᐝ(ᑮᐸ¦m§᪵ᦑC┯DஹᙌlmḄxylO4eiz,ᓰᓫᵯ\xyḄᓝ«ᑖ¬ᡠᵯ\ᙌxy/b®¯°Jᦑ஺±²஺ᦑ⌱VDo916⚓ᐳ22⚓

16᪷#⚪_´µᑖ᪆“0plm”Ḅsᳮ¶·ᔠx|}~ᑖ᪆A⌱⚗᝱Ḅs\ᵯ◤⌕Ḅxy13.6W,ᵫ»ᑖ᪆B⌱⚗¼zᐝḄ¡½¢£¤ᑖ\Ḅiᑖ᪆C⌱⚗ᙌlmḄxylO4eU,ᓰᓫᵯ\xyḄᓝ«ᑖ¬ᵫ»ᑖ᪆஺⌱⚗஺>⚪@⌕ὃC“0plm”+“x|}~”Ḅ¾¿ᐵEÀ⍝ὅÁÂḄᳮ/0,À⍝ᐝ\xyḄÄÅÆÇ஺15.ூRᫀ௃31.40.44ூU᪆௃UV(1)È᪗ᓱËḄÌO.lnun@ËÍᦪ3.1cm=31mm,È᪗ËÍᦪ4x0.1mm=0.4mm,ᦑÏÐÑÒḄᑁÔ31nun+0.4mm=31.4mm(2)ÕÖÄᦪ%¬×Øᨵ4Ä1%Ùᨵ᪗kÕÖÚ%Ḅ1×t=5T=5x0.02s=0.1s,᪷#ᒴÛÜiÝÞ_×1ß1àn1×Ḅᙳ=À%=᰿=F12.3^0—-3.5x0lOyå2m/,s=r0\.4A4Am//s(3)æçḄè&T,JéÝÞḄa஺᫜+Ṻᨵmg-7=maJéᨵT=Ma.(7=b•mg஺Jé2ᑮíçḄè&7àJé2ᑮḄᔠ&F,ᓽF=î•mg=-^-mg=ïðᨵ᫜+ṺḄ¤yÕ¼Jé¤yñJ(ò1;ôxõ᫜+oMṺᡠ2Ḅ&/MgàJéöᒴÜiÝÞḄᔠ&F஺ᦑRᫀV(1)31.4(2)0.44(3)ïU᪆஺(1)᪷#È᪗ᓱËḄÍᦪ÷ø=(ÏÐÑÒḄᑁÔ(2)᪷#ᒴÛÜiÝÞ_×1ß1àn1×ḄᙳU(C%(3)᪷#ùúsᳮ·ᔠ789:;=ᑖ᪆஺Ïùú⌕®²ùúsᳮᙠ»ẠüᘤᩞḄ⌱ÿ
ᑖ᪆⚗⚪ᑖ᪆ᑮḄᦔᨵ᫜ṺḄ஻!"M!#$%&'()᫜Ṻᡠ+Ḅ,-mg./!"0ᒴ234567Ḅᔠ-஺16.ூ<ᫀ௃6AC5.80ூ?᪆௃?@(1)BC⊤EFG)6,ᢱI)“XI”ᑣKᦪ)@6x10=60M(BC⊤EFNᙳᒴᵨᐸRSᵯUGVWNXK஺)

17(2)ᵯ[ᵯ7\)3.0]ᵯ^⊤_ᨬᜧG)3ᓃᑣcdeSfghḄᨬᜧᵯci)lA=0.5/1,ᦑᵯc⊤k⌱m_0n0.64Ḅᦑᵯc⊤k⌱ᵨAM6eSfghḄᵯUi)60,o.ᨬᜧUG100MOḄpqr7sUᘤ)uv⁚xy,k⌱mᨬᜧG)100Ḅr7sUᘤᦑr7sUᘤk⌱ᵨCM(3){fghḄU-/~)@Ḅ~5)45ᑣfghḄᵯUᢝNs~5d)/o
!oa/ஹUḄGᜧḄ(0.54ஹ2.9U),ᑣ/?=,0=5.800M(4)ᵫ.hḄᵯUFḄᓣsᜧᔠᐵ%hFᵯU!ᵯcᜧMḼhFᓣhᵯU⌲ᜧᵯc⌲!Mhᦣ¡⊝%FᢝNsᵯUNsᵯcᢝNs஺ᦑ<ᫀ)@(1)6M(2)4CM(3)᝞<~1M5.80M(4)ᵫ.hḄᵯUFḄᓣsᜧᔠᐵ%hFᵯU!ᵯcᜧMḼhFᓣhᵯU⌲ᜧᵯc⌲!Mhᦣ¡⊝%FᢝNsᵯUNsᵯcᢝNs஺(1)BC⊤ḄKᦪ.EFG᳛Ḅ¥¦M(2)᪷¨cdeSfghḄᨬᜧᵯcᩭª«ᵯc⊤Ḅ_Mr7sUᘤḄᨬᜧGᜧ.eSᵯUG%k⌱mᨬᜧGeSᵯUGN$Ḅr7sUᘤM(3)᪷¨Ḅ~5ὃ⇋!
/ஹUḄGᜧḄ®#ᵯUGM(4)ᵫ.hḄᵯUFḄᓣsᜧ᪷¨hFḄsᓄḄd_?<ᵯcḄsᓄḄd_஺°⚪ὃ±uᙠ“SfghḄᵯU᳛”µ¶·ḄSᵯUḄ⚪⌕¹ºᔜ¼S½ᐹḄ⌱m¿¨ᑭᵨ~ᜐᳮᦪ¨⌕ὃ⇋᝞Ã'!
º⍝fgḄᵯU᳛FÅ18⚓ᐳ22⚓

18ḄᐵÈ஺17.ூ<ᫀ௃?@(1)Ë4xᔣ)ÍᵫÎÏ67ᵫh=@gt2Õᐭᦪ¨?#t=0.305(2)ÚAஹBÝÞ3F)v,à¡xᔣ)ᒴ367ᵫs=aÕᐭᦪ¨?#D=1.0m/s᪷¨7äឤ«æç«ᔣè)éxᔣᵫ?n%=2nw#%=2m/s(3)pᱥÏÝïd_·ðᜫḄòó'4E=-1-2mv2Õᐭᦪ¨?#4E=0.10;<@(1)pᱥᙽᙠø·67Ḅ%ù)0.30sM(2)pᱥᙽÝúAḄ3F%Ḅᜧ!)2ni/sM(3)pᱥᙽÝïd_·ðᜫḄòó')0.10/஺ூ?᪆௃(1)Ë4xᔣ)ÍᵫÎÏ67ᵫ/i=?gt2V?#%ùM(2)᪷¨¡ü67Ḅçæ®ÝúAḄ3Fᜧ!M(3)᪷¨'äឤV#ᑮÝïd_·Aஹ8ᡠþᡂḄ
ᜫḄ஺⚪⌕ᑖ᪆ᱥᳮ⍳Ḅᱥᳮᐵ஺⚪ᨵ!"#$%ᐸ'()*ឤ⌕,-.ᵨ஺18.ூ5ᫀ௃89(1)᪷=>ᐵ
9qU=\mv2?9U=B2q(2)ᵯEFGHIᐻFK⊝9qE=qBv?9E=Bv\ᵫNOPᑣᑨPᵯEḄSᔣᚖVWXYᔣZ஺(3)ᵯEF\]>᪷=>ᐵ
9E=qU+qEdk?9E=+qBvdk59(1)^_ᵯ`aᖴc

19(2)EdEḄSᔣᚖV#WXYᔣZᜧga8uc(3)ijklNnḄ(a1771/+qBvd஺ூ8᪆௃(1)ᙠ^_sᘤMḄ.(ᑭᵨ>ᐵ
w8c(2)ᵫNOPᑣᑨxyz{FSᔣ|}z{FSᔣ~ᵯEFSᔣᵫEdḄᜧg~Sᔣc(3)"᦮.(ᑭᵨ>ᐵ
w8஺,->ᐵ
ᡈ(PᳮnᑭᵨNOPᑣᑨxz{FḄSᔣᑭᵨw8z{FḄᜧgᐭᑮFᑖ᪆ḄX
஺19•ூ5ᫀ௃ᵯḄᵯᙌEḄ^)F\>ὑḄூ8᪆௃89(1)ᱥXZ¡_s¢ᑮᨬᜧ_s^n^_sa¤ᑣᨵ9G=kvm8?9a=((2)aஹᵯ§ᵯ¨/©nªfḄ¬ᓄa95-//?=4/(ᐸ/,aᙌḄ³´
ᦪ)bஹ᪷=E—=·?9ᵫ#EஹRஹLº¬/⌲¼ᜧ½¾ߟtÁÂAtAtLLḄÃ᳛⌲¼ÅgᨬÆÇPn/=/-tÁÂ᝞ÁᡠÊc(3ᓣ☘᛻1ᱥXÎFÏḄÅÐ)᦮)Ḅᩭ"ÒÓ᛻2ᵯḄᵯcÓ᛻1ᱥX(Ḅ^)"ÒÓ᛻2ᙌEḄ^)cÓ᛻2ᵯRÔὑḄᵯ#ÓÕ1F\>ὑḄ஺59পᱥXZ¡Ḅᨬᜧ_᳛a×Ø20⚓ᐳ22⚓

20(2)ᵯ¨/©nªf¬ᓄḄSaE-IR=L^Ûy/-tÁÜ8᪆;;(3)ÞßÓ᛻I~Ó᛻2Ḅ)áᓄÓâãᑏḄ⊤æ᝞ZÁ9Ó᛻1Ó᛻2ᵯḄᵯᙌEḄ^)F\>ὑḄ(1)ᱥXZ¡_s¢ᑮᨬᜧ_sn^_sa¤᪷=K⊝ᩩè85c(2)᪷=Þßéᑖ᪆ᵯ§ᵯ¨/©nªtḄ¬ᓄ᪷=/-tᐵ
Ûy/-tÁÂ;(3)᪷=Þßéᑖ᪆êëã⊤஺⚪ì⌕ὃîᵯGEḄáᓄᐵï᪷=Þßéêëßðñsðᜧ஺20.ூ5ᫀ௃89(1)᪷=óô.(PT—□TøImv2?T=mg+—(2)a.ûüᙠᨬýþÿ
“᤮ᳫ”Ḅ᤮ᜧᑖᡭஹ᪷ᐵ—cos%)=7ngl2(1_COS9)—2+,%=vyCmgh(l-cos%)=mgl(l-cos0)222.ᓃ>஺Ccos%>cos"ᡠ஺2>஺1஺3“᤮ᳫ”ᵫᨬᜧ᤮6஺᤮7ᨬ89:᜜,᪷ᐵE=7ngz>1—cos஺஺k“᤮ᳫ”ᙠ@AB☢ᑁEF᦮ḄᙊᕜJKLᨬM9ᨬ᜜᪷NOJPQmg=B“᤮ᳫ”ᙠ@AB☢ᑁEF᦮ḄᙊᕜJ᪷ᐵE+H>2mgl+|mv^k2CIJ>KmgI2——cosd)WX(1)᝞Z᤮[ᓃ“᤮ᳫ”KLᨬ89:Ḅ\]:“᤮ᳫ”^ᑮ`arḄ

21ᜧmg+c•,1(2)a.ghLijk᪆஺b.ᙠᨬ89“᤮ᳫ”noḄpqrḄᩩtu(mg%-mgl^l-cosO).ூk᪆௃(1)᪷NOxyPQz`aᜧ{(2)h᪷|}ឤᑨᜳ6Ḅᜧbஹ3KLᨬM9ᨬ“m᪷NOJPQ|}ឤPQ,pqrḄᩩt஺“᤮ᳫ”EḄᙊᕜJJLiᑭᵨPᳮḄᜧ᪷ᔣa>ᔣaḄᜧᙠxy|}ឤḄpᵨ஺x22⚓ᐳ22⚓