2020-2021学年北京某附中分校八年级（下）期末物理试卷（附答案详解）

《2020-2021学年北京某附中分校八年级（下）期末物理试卷（附答案详解）》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

2020-2021
ᓅᜧ▬ᑖ᪥
()ᱥᳮᔁ1.ᙠ▭ᓫᑴ᳛Ḅᓫ()A.ᱯ(W)B.ᯖὡ(/)C.&'ᓱ(Pa)D.)*(N)2.ᙠ᝞,ᡠ.Ḅ/0123456᥅8Ḅ()9:;<=>?B.■JK⊤☢LMNOPᵨRSTᳫVD.@A>B⊤☢EᨵGH3.B.WXYᙠ᪋ᩈ\

1]^_ᨵ`ᜧabᑗdᘤ=ᨵfgh4.᝞,ᡠ.Ḅ/klᐹnᵨo34pRᩨᩚḄst5.᝞,ᡠ.Ḅ/kvwxᱥyzḄst{2⚓ᐳ40⚓

26.ᙠ2020
~┶᪗ᡃ⌱P:175Ḅᡂᡭẚᐰ஺᝞,ᡠ.:~ḼᩨoḄ᯿ᱏᑡḄstA.ᩨxḄ¡RxᩨḄ¢ᢝR¤xO⊝RB.ᩨ¦ᑮḄRxᩨḄ¢ᢝR¤xO⊝RC.¦ᑮḄRᙢ☢xḄ¢ᢝR¤xO⊝RD.¦ᑮḄRxᙢ☢Ḅ¡R¤x©ª«ᵨR7.᝞,ᡠ.¬®¯ᕒᙠ±²³⌕ᐜ¶·¸¹¬ºᨬ¼½ᨬ¾¿ᙢ஺ᙠÀ¤²³ÁNὃ⇋ÄÅÆRᑣᑡḄstᨬ
A.¶·ÈᜧÉ®¯ᕒḄÊឋn̬ÍÎB.Ï®¯ᕒ¬ºᨬ¼½oÌᜐ4☟ÒÓ᝱C.®¯ᕒᙠÄ®¯Ḅ²³RxÌNzD.¿ᙢo®¯ᕒxᙢ☢Ḅ¡RÕ4ᙢ☢xÌḄ¢ᢝR8.᝞,ᡠ.ᵨPᔣ\×ØÙÚÛÜÝ“ᔾ”ᐭ┐ã஺ᙠ,ᡠ.Ḅ/0äåḄᱥᳮæᳮçᐸ©éḄstᔣêḄë0ìíᳫîïê,ëᳫ☠òᵨóᧅ“ᔿ”ìíᳫìíᳫ“ᔾ”ᙠóᧅ\

3c..7[ᵨRᢴ¡ᛛᧇᔾûᔾû“ᔾ”ᙠᜋ☢\týᵨᔾþÿᑴ
ᘤ,ᔾᐭᵬᔾ9.ᡂḄ᪗Ḽᐭ!஺ᑡ$%&'(⌕*+ᑡ$ᜧ-.஺/01᎛$34“ᔾ”ᔣᑡ$Ḅ8ᦑ:;&<=Ḅ>ᐰ@Aᑡ$ḄBCD⌕Eᜧ.஺FGH/ᑡ$%&$▬JKLA.MN'(EᜧஹPQERB.MN'(EᜧஹPQEᜧC.MN'(ERஹPQEᜧD.MN'(ERஹPQER10.TUVᐰWXḄᙊZ[\ᘤ☟^_ᙠabc☢=ᐸᑖghᨵ4ஹ8TjkXḄl-URᳫᑖg_ᙠTj☟^RᳫnᐭTjḄop᝞rᡠtT\ᘤ☢Wb஺ᵬஹuT\ᘤḄv(ᑖg/PlwP2ᵬஹuT\ᘤḄxRᳫy;Ḅz{ᑖg/&w}2ᵬஹuT\ᘤx\ᘤ~ḄPQᑖg/P1wP2ᵬஹuT\ᘤxc☢ḄP{ᑖg/w}2’.ᑣᑡᑨḄGKLA.piFC.PI=pD.Ft'>F]2211.᝞rᡠtabc☢=_-Uᵯᵯ=ᨵ-aḄaᑁa☢aWb஺ᵨ{ᢞ-UᙊZᙽlᙽᙢnᐭaᑮᙽVᐰnᙠa/^᦮Uᙽ¡¢~w£¤஺ᑣ¥ᙽ⊤☢§¡¢a☢ᑮ=⊤☢¨ᐭaḄKL©4⚓ᐳ40⚓

4A.{ḄtᦪRᵯḄtᦪᜧB.{ḄtᦪR,ᵯḄtᦪkC.{Ḅtᦪᜧ,ᵯḄtᦪRD.{Ḅtᦪᜧ,ᵯḄtᦪk12.᝞rᡠtabc☢®¯°kᡲ²w³Ḅ´µ¶·¸¹AºḄ᥅¼ᱥA¾10Mᡲ²ᱥB¾3MᱥA¨¿ᔣÀÁᒴ'@ÃÄᯠÆᵨabᔣÇḄ{}ÈᱥAÉᐸᔣÇÊ@Ã஺ᑡËÌḄGK)A.ᱥAᔣÀᒴ'Ã,BÎᑮḄ¾{kÁÏB.ᱥAᔣÇᒴ'Ã,ÐÎᑮḄÈ{ᔆÒÓ6NC.ᱥAᔣÇÔ'Ã,ÐÎᑮḄ¸᥅¼{ᜧÓ3ND.ᱥAᔣÇÕ'Ã,AxBḄÈ{ᜧÓBX'jAḄÈ{^^13.᝞rᡠthᨵaḄ\ᘤ☟^_ᙠabc☢=Ö/2xl0T3ḄJ^m^V、O二。二-ᱥᢞᙠ{஺lᱥVᐰnᙠa{Ḅtᦪ二1二一1二三-一二|一2/3.4N஺×ØÙaḄv(/l.Ox103kg/3,gioN/kg஺ᑡ⌱⚗12.二二m三，二33三三二4二h二4ḄGKL二-5二二5r一,.)/b\A.ᙠaᱥÎᑮḄÈ{/0.4N>\B.ᱥᡠÎḄz{/5.4NC.ᱥᡠÎḄ¾{/6.4ND.ᱥḄv(/2.7x103/co/m3

5B14.¾/700NḄÜÝᵨ᝞rᡠtḄ¸¹ÞlßᩞÃ〈ᑮᜐ஺ᙠãäÃ〈ÜÝᙠ20sᑁl´µ/40åḄßᩞæᔣ=ᒴ'çᓣé5஻?,¸¹ÞḄìíᦔ᳛/80%஺ðTU¸¹Ḅ´µWÒk³¾·᥅¼gIQN/kg஺ᑡËÌḄGKLA.¸¹¾/10NB.ñÜÝÈ{ÁÏḄÏ᳛/62.5WC.ñBᜐᢞòÎᑮᜩôõḄÈ{/600ND.ñöÜÝxᙢ☢ḄP{ḄᜧR/250N15.ᨵTUᙊZ[\ᘤᑖgᨵ÷(WXḄawãjØ஺ᵨ{ᢞḼ-UᙊZᐜÆlᙊZ⌲úænᐭawØKawØûüL஺rᵬஹuᡠtᑖg/{ḄtᦪFýḼᙊZ⊤☢ᙠa÷(wᙠØ÷(Ḅᓄrÿ
ḄA.F=1.2NᙊᙠᐭḄᙠᐭḄ᪵ᜧB.ᙊᐭᙊ!C.ᙊᙠ"#ᑮḄ!%ᜧ&ᙊᙠ#ᑮḄᨬᜧ!%D.ᙊḄ()*&Ḅ()16.᝞,ᡠ./0*12₩4ᓟḄ67ᑡᑨ:ḄA.*12ᙠ₩4ᓟḄ;<*12ᡠ#Ḅ=%>?@ABB.*12ᙠ₩4ᓟḄ;<?ḄCDE᝱GᢝIJK6⚓ᐳ40⚓

6C.*12ᙠᔣPQRCDḄ;<S#=%D.*12ᙠ₩4ᓟḄ;<?ᡠ#=%ḄTᔣUVWXᔣ17.,Ḅ67⁚⌱[ᡃ]^_`ᢈ℉cdᜩfgᱥiᐸklḄᵬ:opqs:tuv┱:A.ᵬ,“o᫔q”,ᑜḄ᫔>Ḅcᵨ%ᦋJAqḄCDE᝱B.s,“tuv┱”,ᵫᜐ/#ᑮឋcᵨC.,“”,PḄ#ᑮḄḄ!%ᜧD.,“"”,☢ḄḄ#ᑮḄᜧ18.CDᙠᑁ☢PgḄ⚗ᝍ⚗¡ᐸᒹ£Ḽ¥ᱥᳮ§஺☢,Ḅ©7ᙳ«CDᨵᐵᐸᳮ®┯°Ḅ,±ᳫCDᕒ´µ¶;´·᦮ḄCD¹᝱º»µᵨᩭº»Ḅ½ᩞᧇIÀ/AÁÂIÀᜧ*Ḅ᥅Ä%B.,±ᳫCDᕒÅḼÆᔣÇCDÅ%>@ABC.,ÈÉÊḄᙠ☢PºDḄËÌÍQ*

7D.,⚞ᳫÏᕒ¶;ÐRᑵQ*Aᡠ#᥅Ä%,ÒḄR)Óᜧ19.᝞,ᡠ.ÔᱥᐭᵬÕÍÖ!&ᵬ☢,×ÕᐭsÕᓾᐭÙÚ᝕A.ᱥᙠᵬ#ᑮḄ!%ÜᜧB.ᱥᙠs#ᑮḄ!%ÜᜧC.ᵬḄ()ᜧ&sḄ()D.ᵬ>ÝᘤÙḄß*&s>ÝᘤÙḄ20.,ᵬᡠ.ᵨ0DºàᒴRWXâᓣ=/4500NḄᱥA,ᙠᔁåËæ%çḄcᵨᱥAWXèDḄéÈêëJᓄḄᐵí᝞,s,î஺ᡠ.ᔁåËḄឤßB᳛/1000W;ᵨñòᒴRâᓣᱥ8ᱥ8WXèDḄéÈêëJᓄḄᐵí᝞,s,îᡠ.,Ióô=à«õëḄ᥅Ä஺ᑡklḄA.ᱥAWXèDḄR)/20cm/sB.DºàḄ=%ᜧ*/400NC.2öᑁºà>ᱥB@ḄᨵᵨB/1900JD.âᓣᱥ8DºàḄËÌᦔ᳛/95%21.᝞,ᡠ.ᜋPᢞḼSúᳫûᙠ,üýúᳫᡠ#=%Ḅ.þ,஺K8⚓ᐳ40⚓

822.᝞,ᡠ.஺8
஺ÿ
Ḅᩨᩚᵨᙠᩨᩚ8Ḅ.ABᔆḄᵨᙠᩩ஺1AB,AC1OB.⊤Ḅ.(⌱!ᡈ“AC”)23.ᙠ#$“&'᥅)Ḅᜧ+,-./ᨵᐵ”Ḅ34+5⌱6⊤☢89:;᪵Ḅ=>?ᩈᙽBᡂDEF᝞HIJ(1)+5ᙠKLM☢ᵨNOPQKLᔣST'ᩈᙽUVWᒴYZ'NOPQḄᦪ᝞22ᡠ᪷^Ḅ_`a_ᩈᙽᡠb&'᥅)M(2)+5cᩈᙽde>ᔣᑗghPi&'᥅)jkᩭḄh᝛ᵫoipJ&'᥅)Ḅᜧ+qrs☢tḄu+vu+஺wx᝛ᙠ#$y:zᙠḄ{⚪o(3)}wᑭᵨᘤᩞQ#$&'᥅)Ḅᜧ+rs☢tᔲᨵᐵḄ34>ᫀ(ᑏp⌕ᓽa)஺24.ᙠ“#$?ᑁḄ./”Ḅ34+ᵨᡠḄ34DEF34J

9Q?;/i/cmᔣS☢hi/mm☢2/6;¡4/i/nun131862142823H18621428K33¢1862142849H1582428453H185.5215.529£K69H156.5243.587(1)+ᙠ¤¥¦§¨ᵨ©ᢣ«¬®¯#ᜮḄ¦U±²³´☢µ¶·ᨵjᓄ¹º»Q(⌱!“¼½”ᡈ“¾¼½”)¿(2)¤¥ÀᘤᩞÁ+Bᡂ34ÂÃ34ᦪ^ÄÅᙠ⊤•Ç1ஹ2ஹ3ḄÉÊᦪ^aipˬJ?Ìͦ?ᑁᔣᔜ>ᔣḄ(3)ÇḄ³Êᦪ^aipˬJ;Ìͦ?ᑁḄᜧ+Ï?ḄÐ;ᨵᐵÑ஺(4)+ºÍÒᙠὁÔᢣÕHᵨÖ᜜Ø?#$F?ᑁ;ḄᐵÑÂ᪷^34ᦪ^ÙpF᝞ᡠḄÚ஺ᵫÚa_»?8cÛᜐḄ______Pa஺25.᝞ᡠḄ34}wÝÞHᑡ{⚪:(1)Ẇ$“âãᱥ?Z'Ḅ”åæḄçèᩞᧇᑖëìíஹîïஹᩈðFᙠ34ḄñẠDóÒôᳮpᱥ?¾b¦ḄZ'ö᝱ᙠKLM☢çè34ᩞᧇḄøùA.ìíஹîïஹᩈðB.ᩈðஹìíஹîïú10⚓ᐳ40⚓

10C.ìíஹᩈðஹîïDîïஹᩈðஹìí2
Ẇ$“âãᱥ?Z'Ḅ”åæḄçèᩞᧇᑖëìíஹîïஹᩈðFU+ýþÿᑮ
☢Ḅ☢Ḅᵫ஺ᙠḄẠᳮ"#$%&Ḅᱥ()*+,ᵨ.஺26./01“34ᩨᩚḄ⊝ᩩ9”Ḅ஺1
;ᩨᩚ᝞=ᡠ?.@AB⊝CDᔣF&GH$“I”ᡈ“K”L,Nᩨᩚᙠ_____PQ⊝஺ᯠSTᔣᩨᩚᢞVṹ஺2
/0X⁚ZᩨᩚSᙠ[\]^ᢞᦪ`)0ḄVṹGabVṹc`d0ᩨᩚdefghidjL᝞=ᡠ?஺klmnoḄpqoGHrD
4.tuvSᩨᩚ)w⊝K^x.B.]^Vṹyᔣ[\F&zᩨᩚ{k⊝C.ᙠK^Vṹ|}bVṹᩨᩚ{k⊝஺.~K^Vṹᙠ[\I^/bPQᵨ+ᩨᩚ{k⊝27.᝞=ᡠ?Ẇ4+Ḅ,ᵨᦔᨵᐵᵨᙽஹbஹbᜧṹ1᝞$জBᙠ¡ঝᙠ}bᜧṹ¡ঞB☢ᦋᙠ¥}bᜧṹ஺᪷§Ḅ¨m©=ª«¬®ᑡ°⚪$1
ªp²³´µᩭ·¸“+,ᵨᦔ”Ḅ¹℉»Ḅ஺2
ᵫ¼ஹ½={"¾¿$஺Àᙠ#GᵬLG¼LG½L

1128.ᙠ34“ÂÃÄÅÆÇᦔ᳛ÉÊḄ”.0ËÌ¥ᑭᵨ᝞=ᡠ?ḄÄÅᑖÏ1஺⊤ptËÑÒḄÓᑖᦪ§஺ÔÕᑖ᪆ᦪ§®☢Ḅ°⚪:ØgᩞÅÏGGᱥ/NF/Nh/cms/cm஻/%c1ÝÞ0.30.95113370.22ß0.320.78123685.43ß0.1520.7510304ß0.1510.4123683.3(1)ÔÕ᪷§⊤ªḄᦪ§ᙠ=ªà#ÄÅḄØgáâ஺(2)ÔÕã#ä1ÅḄᱥåG=N(çᶇ᦮ᦪ)ä2ÅḄë6=_____Jä3ÅḄÆÇᦔ᳛ì=(çᶇîU0.1%)஺(3)ÔÕᑖ᪆⊤zᦪ§lï⌕ñÉAÄÅḄÆÇᦔ᳛ª{1Ḅò,mp»(ᑏ#ᩩᓽ{)29.ᙠ34ö+⊝ᩩ9Ḅ.B÷øùcᓱᱏ]üýḄþgᑖÏÿ
ᔾᙠḄᙠḄᢞṹ᝞ᡠ஺ᵨᙠᓱᱏḄᜧ!"#ஹ%ᔣ"'஺()*+,“./01ᵨᙠ23ᩩ56789⊝”ᑣ=ᑡ?@ABCḄDAEᢄᓱᱏᙠGHᢞ3ṹIEB.EᢄᓱᱏJᐸL5ᔣ=MN3OIEC.EᢄᓱᱏPᐸQRᙠL59☢TU90஺IEDEᢄᓱᱏVGL5ᔣMN3OIE30.!□ᑭᵨᡠḄ?@ẆZ[ᜧ!\᣸^_ᡠ`aḄᐵcdefgḄᦪᑖj⊤lFiஹm2ஹm3ஹᐭ஺(1)o1q?@frḄᦪsl,&=15N,F=1.2N,F=1.2N,F=0.4N,234vVwq?@fxygzḄᦪs{ᙠ=⊤QḄ|}~஺?@ᦪs⊤o12⚓ᐳ40⚓

12ᱥᡠ`!᫜ᱥ᣸^!᫜ᡠ`ᱥ᣸^_ᡠᱥᡠᱥᙠ_Qq[_ᡠ`ḄaḄa`Ḅa`afgḄᦪᦪG/NF/NFG/NG᫜/NG᣸/N1—2᪷sᦪs⊤QḄᦪs!□q?@rᑮḄD,ᱥᡠ`[Ḅᜧ!⌱{“ᜧ”“#”ᡈ“!”ᱥ᣸^_ᡠ`ᑮḄaḄᜧ!஺3(QḄ__᝞=ᡠᑣfrḄᱥ᣸^_ᡠ`ᑮḄaḄᜧ!⌱{“ᜧ”“#”ᡈ“!”ᱥᡠ`[Ḅᜧ!஺31.!+¡g?@*+,“ᱥᙠ_Qᡠ`Ḅ[Ḅᜧ!\᣸^_Ḅ¢ᡂB¤”?@¥ᜓᨵ¨ᔠ?@⌕«Ḅ᝞=ᘤᩞ,?@¥ᵨᛛᧇᜧ°5±10c”?ஹµ40cmஹ_ஹ¸¹¢Ḅṹ6defg»1?@¼½,জVdefg஺Vdefg6ṹ᝞ᡠ¿À=ᱥaG,{ᐭ⊤Q»

13ঝᙠᛛᧇᜧ°ᝰQÅᐭ〉xḄ__☢µ6ṹᢞᙠ3ÇḄµÈ஺É6ṹQḄo3ṹÊËᙠᛛᧇᜧ°Ḅ_QÌÍ_____,=ᓃᵫÌ2=defgḄᦪFᱥ{ᐭ⊤Q»ঞ⌲ÓÔHÊᐭ_QḄṹᦪÕ᯿¼½ঝ×Ø5qᑖj=|}ḄᱥᳮxÌ{ᐭ⊤Q»ট᪷sÛÜÝ[=,gzÞßq?@ṹᡠ`Ḅ[{ᐭ⊤Q஺(2)?@ᦪs⊤,32.v▅áâRNãḄ3ᑖäåÌæç32⚪éRNãḄ3ᑖäê_ëìíî“ëïì”ðDᢣê_Qò_ᦻ⌕ôᙠL5%ᔣÞõöïᡈ÷¿øᒓïḄ_ì஺᝞úê_ëìDìûÈᜧஹ=ìûÈ!Ḅü᝱þᡂÿ

“”஺‷ᙠ“”ញᒓᣵᔣ“ᣵ!”ᜧ#ᦪ%&‷Ḅ(ᐰ!300஻?‷,-.ᑴᙢᣵᑮ(ᐰ!234ᜧḄ56ẚ8⌼ᡂᜫ<஺=>372‷?@AᡊᜓDEFGH“ᣵ!”ḄIJ஺“ᣵ!”Ḅ372‷ḄKL‧NOPQẚR‷STᓽPVWXY“RNZ[!ᔣᡠᨵ_`a!”஺,ᑮ10bcdញ`a▀fᡭhᡠᨵ_hi`aY1ᑖcᑁlmn▀fᐵpᦪᓝrᵯatᜓᐵpu2ᑖcvᐰ‷ᔜ‧xy‧z{|“ᣵ!”}ᯠ஺3ᑖcv“ᣵ!”!
hi᠒ᓣ஺372‷fᐵᓄ◅ᜱ⌼ᡃ>‷lḄ᜻஺(Ḅ
lx/03kg/m3,g10N"g)(1)‷⍗ᑮ“”3‷ᜫ⊝ញᒓ¡Ḅ¢£¤஺A.
ᜧ¥6ᜧ¦6,B.
§¥6§¦6ᜧ¨14⚓ᐳ40⚓

14C.
ᜧ¥6,¦6§D
§¥6§¦6,(2)‷300஻?!
3-ᑮḄ5³´᪗¶ᜧa5Ḅ·஺(1᪗¶ᜧa51x105Pa)(3)“ᔣᡠᨵḄ_`a”Ḅ½Ḅ¤஺(4)‷“ᣵ!”ᨵᡠ¿|,TᓽÀ¤£‷ᐹᨵ஺(5)Â‷ÃÄÅ2.6x103t,ÉÊ3x103rH3,⌕ÎÏÐ☢ᐭÓ⌕ᔣ_ᐙᐭm3Ḅ஺33.Ö☢lᨵ?n×Ø×ØÙÚ᝞ÜᡠÝØ!10c/n,ØáḄ☢Ê50cm2.â§ᳫAäᐭ×Ø☟3×Ø×VḄÉÊ10-4^3,èéê6Ýᦪ3N.ìíḄ
p^=1.0x103kg/m3,g10N/kg஺ð:(1)òØḄ5³p#(2)òØḄ56F#(3)§ᳫAᙠ×Ø-ᑮḄ¥6ô¥u(4)§ᳫAḄ¦6G”

1534.᝞Üᡠݤᵨ÷øùú〈üýᩞᧇAḄ
ᙠᔁOᔁḄFᵨ900NḄᩞᧇA0.2m/sḄᒴᓣ!Ḅ"ᦔ᳛஻&90%,'()!*+Ḅ᥅-஺/0(1)F-(2)ᔆ23Ḅ3᳛P#(3)!ᡠ5ḄG஺஺616⚓ᐳ40⚓

16:ᫀ)<᪆1.ூ:ᫀ௃Aூ<᪆௃<0ᙠᱥᳮCDAஹFᱯH3᳛ḄᓫJᦑALᔠ⚪O8ஹᯖὡH3)ᔜSTUḄᓫJᦑ8'Lᔠ⚪OCஹVWᓱHYZḄᓫJᦑC'Lᔠ⚪ODஹ[\HḄᓫJᦑ஺'Lᔠ⚪஺ᦑ⌱0A஺᪷_`aᱥᳮUbᐸᓫJḄde:஺f⚪ὃhḄHᡃj`aᱥᳮUbᐸᓫJḄdeklmnopឋroḄὃhstuᓫv᧕<:஺2.ூ:ᫀ௃Aூ<᪆௃<0Aஹxyz{|!Hᵨ}~ᩭ᥅-ᦑALᔠ⚪O8ஹ■⊤☢'HᙠY:ᜧ☢Ḅᩭᜧ᥅-ᦑB'ᔠ⚪OCஹᵨeᳫHᙠ☢ᜧYᩭᜧ᥅-OᦑC'ᔠ⚪O஺ஹ!⊤☢ᨵ¡HᙠYᜧ☢Ḅᩭᜧ᥅-ᦑ஺'ᔠ⚪஺ᦑ⌱0A஺(1)ᜧ᥅-Ḅ¢£0ᙠ☢ᜧYᩭᜧ᥅-OᙠYᜧ☢Ḅᩭᜧ᥅-஺(2)᥅-Ḅ¢£0ᙠ☢Yᩭ᥅-OᙠY☢Ḅᩭ᥅-O☢ῃ¥Oᵨ}᥅-~᥅-஺¦⚪ὃh᥅-ᜧḄ§¨©ªbᜧ)᥅-Ḅ¢£᥅-«⚪ᙠ¬D®ᵨ¯`°±<:f⚪²«⚪⌕ᑭᵨµᑴ·U£Ẇ¹.

173.ூ:ᫀ௃Dூ<᪆௃<04ஹº»º¼HᙠYᜧ5☢½ᩭYZOᦑA'ᔠ⚪¾ஹO8ஹ¿ÀÁᙠ᪋ᩈHᙠYᜧ5☢½ᩭYZ0ᦑ8'ᔠ⚪OCஹÄÅᨵÆᜧÇÈHᙠYᜧ5☢½ᩭYZOᦑC'ᔠ⚪-1V-ÉO஺ஹᑗËᘤ|ᨵÍÎÏHᙠY5☢½ᩭᜧYZOᦑDLᔠ⚪஺ᦑ⌱0DoᜧYZḄ¢£0ᙠY:5☢½ᩭᜧYZOᙠ5☢½ᜧYᩭᜧYZ஺YZḄ¢£0ᙠYᜧ5☢½ᩭYZOᙠ5☢½,YᩭYZ஺¦⚪ὃhÑᜧ)YZḄ¢£bᐸ®ᵨH⍝ÓẠ⚪஺4.ூ:ᫀ௃Dூ<᪆௃<0AஹÕÖ┴ᵨDØᜧnÙØHḕᩨᩚ஺8ஹ᪶᪻ᜳᙠᵨDØᜧnÙØHḕᩨᩚ஺CஹàáᑐᙠᵨDØᜧnÙØHḕᩨᩚ஺஺ஹãäᜳᵨDØnÙØHåᩨᩚ஺ᦑ⌱0D஺æᔠᱏ)¬èéᐜᑨìᩨᩚᙠᵨDØ)ÙØḄᜧᐵîïᑨìðHmnñS²òḄᩨᩚ஺ᩨᩚ᪷_ᐸḕklóᑖ&õ²0ØᜧnÙØḄᩨᩚ&ḕᩨᩚOØnÙØḄᩨᩚ&åᩨᩚOØönÙØḄᩨᩚ&öØᩨᩚ஺5.ூ:ᫀ௃B618⚓ᐳ40⚓

18ூ<᪆௃<0÷øḼᩨú'÷ûᩨúüᔣḄᩨúᔣþᨵÿ
ᩨᨵ஺ᔠ⚪஺8ஹᱥᙢ☢ᑮᱥᔣḄ"ᱥᔣ#$
ᱥ஺ᔠ⚪஺Cஹ%&'᫜')*+'᫜ᔣḄ"'᫜ᔣᨵ#
'᫜ᨵ஺ᔠ⚪஺஺ஹ,-ᜮᨵ,-ᜮᔣ/Ḅ"-ᜮᔣ/ᨵ#
-ᜮᨵ஺ᔠ⚪஺ᦑ⌱28஺3⚪⌕ᢕ6Ḅ78⌕9:2;ᵨᙠᱥ>Ḅ"?ᱥ>ᙠ"Ḅ@ᔣABḄ
஺CὅEF஺ᨵ"ᨵ
"ᱥ>Gᱥ>8Hᙠ"Ḅ;ᵨIAB$
"ᱥ>J஺6.ூMᫀ௃BூP᪆௃P2AஹᩨḄR"SᩨḄTᢝ"V7"ᨵ;ᵨᙠWᱥ>X)⊝"ᦑA┯[?8ஹᩨ\ᑮḄ]"SᩨḄTᢝ"ᜧ_`aஹ@ᔣ`bஹWcde;ᵨᙠWᱥ>X)⊝"ᦑBfg?Cஹᙢ☢ḄTᢝ"ahSᩨ]"ḄS\ᑮḄ]"Sᙢ☢ḄTᢝ"ᜧ_`aᡠjX)⊝"ᦑC┯[?஺ஹ\ᑮḄ]"Sᙢ☢ḄR"Ḅ@ᔣX`WḄkᜧ_`WX`l;ᵨ"ᦑ஺┯[஺ᦑ⌱:Bo(1)C")⊝ḄᩩoX2জᙠWcdḄ7"?ঝ;ᵨᙠWᱥ>?ঞᜧ_`a?ট@ᔣ`b஺(2)`l;ᵨ"ḄᩩoX2জᙠWcdḄ7"?ঝ;ᵨᙠ7Wᱥ>?ঞᜧ_`a2ট@ᔣ`b஺᪷uC")⊝ḄᩩoS`l;ᵨḄᩩov*ᑨx஺PMyz{⚪Ḅᐵ}XfgḄ\"ᑖ᪆SC")⊝ᩩoஹ`l;ᵨ"ḄgSᳮ

19P஺7.ூMᫀ௃DூP᪆௃P2AஹXᑭᵨᕒḄឋ&ᡂᜧឋᦑA┯[?3ஹᕒᨬᕒᙠ')@ᔣᨵGḄ0,ᦑ2┯[?CஹᕒᑮᨬḄBᕒᨵ]"kᙠ]"@ᔣ#$
ᡠj]"ᕒᦑC┯[?஺ஹᕒᙠᙢᕒᙢ☢ḄR"Sᙢ☢ᕒḄTᢝ"X`l;ᵨ"ᜧ_`aᦑ஺fg஺ᦑ⌱2D஺(1)ᱥ>¡ᢝ¢ᩭ¤᝱¦Ḅឋ§¨ឋᑗᱥ>eᨵឋឋXᱥ>Ḅª«ឋឋᜧ_¬ᱥ>Ḅ§®ᜧ_ᨵᐵ?(2)᪷uᕒḄ¤᝱ᑖ᪆?(3)Ḅ78⌕ᩩo2ᨵ";ᵨᙠᱥ>kᙠ"Ḅ@ᔣ#$
?(4)`l;ᵨ"Ḅᩩo2ᜧ_`aஹ@ᔣ`bஹ;ᵨᙠ7ᱥ>;ᵨᙠWᩩcd஺y⚪¯⌕ὃ±²³ឋ´µḄᳮPஹ¶·Ḅ9:ஹḄ79:j¸`l;ᵨ"Ḅᱯ²º⌕»ὶ½¾▭ᵨᡠ²ÀÁP³ÃḄ¾▭{⚪஺8.ூMᫀ௃CூP᪆௃P2ᵨ┐ÅᔾÇÈÉ⌕ᐜË┐ÅᑁḄÍÎᢴÐᙠ᜜ÒᜧÎRḄ;ᵨIÈÉÓÔRv┐ÅÕ?Aஹᔣ'Ḅ7Ö×ᳫÙÚ'7ᳫ“ᔾ”ᙠXᑭᵨ'ḄÝÞßRàÞ_ᦑAᔠ⚪?8ஹᵨ"ᔿâᧅÎÝäâᧅḄåßÝÐæçᜧÖ×ᳫḄèÎÝÝᜧRàæç_Ö×ᳫḄIè\ᑮḄᜧÎRX¦ḄᡲḼÖ×ᳫëᣵIᩭᦑBᔠ⚪஺Cஹᛛᧇᔾï⌕ðGᙠᜋå◤⌕ᐜᵨ"ᢴRᛛᧇᔾïËïᑁḄÍÎᢴÐᯠôᔾõ20⚓ᐳ40⚓

20ïÓÔ᜜ÒḄᜧÎRøRᙠ$ùẈᦑCᔠ⚪?஺ஹᵨᔾüýᑴÿᘤᔣᔿAᜧᦑᔾᐭᵬᔾᑭᵨᜧḄᙢ!ᦑ஺#$ᔠ⚪'஺ᦑ⌱)C»(1)Ḅ/ᜧḄᙢ!/0/Ḅᙢ!/ᜧ0(2)ᵫ3ᜧᨵ567ᐹᨵឋᦑᜧ:;ᙢᳫ⊤☢Ḅᱥ@A0ᜧᙠACᨵDEFḄGᵨ᝞)ᔾIᧇஹLMᔾNOஹᔾPQᢞSTT஺U⚪ᑭᵨVᜧḄWᙠஹXᐵZ[ᑖ]^Ḅ_ᵨ6ᩭabcdefcg“ᔾ”jᒹl#mḄᱥᳮop⌕r'sᑖ஺9.ூxᫀ௃Aூa᪆௃a)|}~ᑡ~ᑡḄDᜧ|~ᑡḄ^ḄDᜧ,|᜜Ḅ#|ᑮ᜜ᜧ3|ᑁᑮḄ|ᙠᜧḄ_ᵨD᧕ᔣᑡAᦑ஺ᦑ⌱)AoḄᨵᐵ/ᜧ/஺|ᑡ^Ḅ[|᜜ḄḄᜧ஺ḄᐵZᵨabᨵᐵḄ⚪஺10.ூxᫀ௃Dூa᪆௃a)Aஹᵫ3ᳫ¡ᙠ4ᡠPᳫPzᦑA┯®0Bஹᵫ3ᳫ¡ᙠAᡠ&=GḄ§ᳫ¨¡ᙠBᡠF2=Gᳫ,ᡠ&=²2,ᦑB┯®0cஹᵫ3³ᘤ´µm᪷·¸QP=pg%¼½ᜧḄ;ᘤ¾¿ḄᜧᡠPi>P2,ᦑC┯®0DஹᵫÀ¼ᓃ>ÂÃÄÅPl>P2᪷·m=pU¼m>m,ᡠG1>G2,ᵫ123ᘤ;ᙢ☢Ḅ6T3ᘤḄ56ஹḄ56[ᳫḄ56ᡠFJ>F',2

21ᦑ஺ÊË஺ᦑ⌱)D஺(1)Ìᱥ¡ᙠPᱥ.P/,Ìᱥ¨¡ᙠPᱥ=P0;(2)᪷·¡ÍᩩÏᑨÑᱥᑮḄ¡6ᜧ0(3)´µm᪷·¸QP=P஺Òᓽ¼ᑨÑÔ;ᘤ¾¿Ḅᜧ0(4)ᘤ;ᙢ☢Ḅ6T3ᘤḄ56ஹḄ56[ᳫḄ560ᵫÀ¼ᑨÑÔ³ÕḄᐵZÖ◤᪷·½¸QḄØÙḄᜧᐵZᓽ¼ÚÔḄ56ᐵZ஺U⚪ὃÜVÝA;¡ᩩÏஹ¨¡ᩩÏஹ¸QḄᳮaÞᵨ஺᪷·ᱥḄ¡Í(¨¡ஹ¡)ËßᳫXḄ½ᜧᐵZU⚪Ḅᐵà஺11.ூxᫀ௃Bூa᪆áa)᪷·âãäåæᳮ¼çᐭḄᱥᑮḄ¡6ḄᜧT3ᐸ᣸êḄᑮḄ56ëìᙽîîᙢçᐭOïᑮìᙽðᐰçòᙠOÅó᦮gõöìᙽ÷øù¾ú᣸êOḄÕᐜᜧü#᪷·²=G-Fý¼Úþ6ÿḄ
ᦪᵫᙽᙠ☟᪷ᳮᙽ!ᑮḄ#$%᣸'Ḅ(ᙽ)Ḅ*$ᜧ,#$-%᪷$Ḅ.ᵨ0-1Ḅᙽ2345*$ᜧ%#$ᡠ7)ᵯ9:Ḅ*$;ᓽᵯ9:
ᦪ;ᦑ8>?ACC┯A஺ᦑ⌱DB஺᪷E=G-F#GH$IḄ
ᦪ᪷ᳮᐭKLḄᱥL!ᑮḄ#$Ḅᜧ%ᐸ᣸'ḄKL!ᑮḄ($ᙽ!ᑮḄ#$%᣸'Ḅ(᪷$Ḅ.ᵨ0-1Ḅᙽ2345*$ᜧ%#$஺O⚪ὃRSTUVH#$ஹᳮḄXᵨYZ;ᜧ஺12.ூ^ᫀ௃Bூa᪆௃aDAஹᱥLAᔣdᒴfgh8ᙠ($ḄiᔣjklSmn($opᦑA┯Aq22⚓ᐳ40⚓

228ஹᱥLAtᔣdghᙠtiᔣj!ᑮᱥLB)ᱥLAuvḄtᔣdḄw$x3NஹtᔣyḄ᥅{$.ᵨ|ᱥLAᜐᒴf~gh᝱ᑣ᥅{$w$0t⊝$ᡠ7tᔣyḄ᥅{$,ᔣdḄw$ᜧ-%x3NᱥLAtᔣdᒴf~ghtiᔣj!ᑮtᔣyḄw$ஹtᔣdḄw$3N(ᱥLB)ᱥL4uvḄ)ஹtᔣdḄ᥅{$3N.tᔣyḄw$tᔣdḄw$ஹtᔣdḄ᥅{$0t⊝$tᔣyḄw$=tᔣdḄw$+tᔣdḄ᥅{$=3N+3N=6N,ᦑ8>?CஹᱥL4tᔣyghtᔣdghᵫ*$;☢Z;ᱥLA!ᑮḄ᥅{$;ᡠ7ᱥLAtᔣyfgh!ᑮtᔣdḄ᥅{$03MᦑC┯ADஹᱥLAᔣyvfghA)BḄw$B)AḄw$04)-1.ᵨ$ᜧ-%ᦑ஺┯A஺ᦑ⌱D8஺(1)ᨵ$ᱥLᙠ$ḄiᔣjklSmn$op(2)ᱥLAᙠᱥLBḄ.ᵨᔣdᒴf~ghᱥLAᙠtiᔣj!ᑮtᔣdḄw$tᔣyḄ᥅{$.ᵨ᪷$t⊝ᩩ᥅{$ᜧ஺ᱥLAᔣyᒴf~ghᱥL)t☢Ḅ*$;☢Z;ᱥLAt☢Ḅ᥅{$;஺ᱥLtᔣyᒴf~ghᱥLAtiᔣj!ᑮtᔣyḄw$ஹtᔣdḄw$ஹtᔣdḄ᥅{$.ᵨtᔣyḄw$tᔣdḄw$ஹtᔣdḄ᥅{$0t⊝$᪷t⊝$ᩩtᔣyḄw$஺O⚪Ḅ(0᥅{$ᜧḄᑨ᪷᥅{$ᜧḄ|ᑨᱥLAᔣyᔣdghḄ᥅{$ᜧ;᪷ᱥLAoᒴf~ghᑭᵨt⊝$ᩩw$ᜧ஺13.ூ^ᫀ௃Dூa᪆௃aDA.¡ᱥL¢ᐰᙠ¤¥H$IḄ
ᦪx3.4N,ᑣᙠᱥL!ᑮḄw$Ew=3.4N,ᦑA┯Aᕒ¡ᱥL¢ᐰᙠ᣸'ḄL§¨=V=2x10-43,m

23ᑣᱥLᡠ!Ḅ#$©#=0ª஺«=1.0x103kg/m3x10N/kgx2x10-4m3=2N,ᦑ8┯AC.ᵫF#=G-FᡃGᱥLᡠ!Ḅ($G=E#+Fᢗ=2N+3.4N=5AN,ᦑC┯ADᵫG=mgGᱥLḄ®Um=m=AW=0-54kg,ᱥLḄ¯Zp=^=9lU/V/rCjyV°ᘤj=2.7X1஺33/3,ᦑ஺>?஺7nᦑ⌱DDo(1)¡ᱥL¢ᐰᙠ᪷¤¥H$IḄ
ᦪᙠᱥL!ᑮḄw$(2)¡ᱥL¢ᐰᙠ᣸'ḄL§³´ḄL§-%᪷F#=PKguµᱥLᡠ!Ḅ#$(3)᪷E#=G4EwᱥLᡠ!Ḅ($(4)᪷G=mgᱥLḄ®Uᑭᵨp=ⅉᱥLḄ¯Z஺O⚪ὃRSᳮT(V#$·°ஹ($·°ஹ¯Z·°ḄXᵨ⌕¹ºᱥL᣸'KLḄL§³´ḄL§-%஺14.ூ^ᫀ௃Cூa᪆௃aDA»ᩞḄ($G=mg=40kgxION/kg=400/V,½¾w$oḄᨵᵨp“À=Gh=400Nx5m=2000/,ᵫq=”x100%Gw$oḄÁpW#=4=Â=25007.wÁÃ480%JᵫÄÅÆÇÈ9ḄᨵᦔÊᦪË=2,ᑣÈ9³ᵫÌÍhḄmns=n/i=2x5m=10m,ᵫWÁ=FsGÅÆÇÈ9³ᵫÌw$F=0=Îᦔ:=250Ns10m|;IÈ(Ð᥅{ᡠ7ᵫF=(G+Gh)GhÅÆ($Gh=nF—G=2X250/V-400/V=100N,ᦑ4┯AB.Ñl½¾w$opḄp᳛P=0=Ó=125WᦑB┯At20sC.ᵫÔ5ÅÆḄ®U-%G=mgGG^=100N,q24⚓ᐳ40⚓

24ÑlBᜐᢞÖ!ᑮᜩØÙḄw$Fᶯ=G^+2F=100/V+2x250N=600N,ᦑC>?DÑlÛ½¾)ᙢ☢Ḅ*$E*=G3—F=700/V-250N=450N,ᦑ஺┯A஺ᦑ⌱DCo%(1)᪷G=mg»ᩞḄ($᪷Þ=G/i½¾w$oḄᨵᵨpᑭᵨß=—x100%w$oḄÁp᪷Ä
ÅÆÇÈ9ḄᨵᦔÊᦪᑭᵨs=nhÈ9³ᵫÌÍhḄmnᑭᵨW=FsÅÆÇÈ9³ᵫÌw$;IÈ(Ð᥅{ᑭᵨF=(G+Gh)hÅÆ($(2)᪷P=?Ñl½¾w$opḄp᳛D(3)᪷Ô5ÅÆḄ®U-%G=mgGáÅÆḄ($Ñl8ᜐᢞÖ!ᑮᜩØÙḄw$%áÅÆḄ($vjÔÊÈ9Ḅw$â(4)ÑlÛ½¾)ᙢ☢Ḅ*$%³´Ḅ($ãÈ9Ḅw$஺O⚪ὃRS($·°op·°ஹÅÆÇäåᦔ᳛·°ஹÅÆÇw$·°ஹp᳛·°ḄXᵨ%⌕¹º8ᜐᢞÖ!ᑮᜩØÙḄw$%áÅÆḄ($vjÔÊÈ9Ḅw$â஺15.ூ^ᫀ௃Dூa᪆௃aDAஹᵫᵬÄ7çèéZx25cäᙊëLìí¢ᐰᡠ7ᙊëLᐭḄéZxh=25cm=0.25mᵫîÄ7ç褥H$IḄ
ᦪx0ᙊëLᐭïKLḄéZxð=20cm=0.20mᙊëLḄ3☢§-ñ᪷U=S/iᵬÄᙊëL᣸'ḄḄL§⌕ᜧîÄᙊëL᣸'ḄïKLḄL§ᦑ4┯A8ஹᵫÔÄᙊëLḄ($xG=7.2MᵫÄᵬᙊëLᐰòᐭä¥H$IḄ
ᦪx1.2N,ᑣ!ᑮḄ#$x7.2N-1.2N=6N,#$($ᡠ7óᙊëLôᐭᙊëLõöᦑ8┯ACஹᵫîÄ7礥H$I
ᦪx஺ᙊëLᨵᐰòᐭïKL÷⊤ùᙊëLᙠïKL0ú#!ᑮḄ#$%($ᡠ7ᙊëLᙠïKLḄ#$x7.2N,ᡠ7ᙊëLᙠ!ᑮḄ#$ᙊëLᙠïKL!ᑮḄᨬᜧ#$,

25ᦑc┯A஺ஹᙊëLᙠKLú#ᑣᙊëLḄ¯Z⌕ïKLḄ¯Zᦑ஺>?஺ᦑ⌱DDo(1)᪷ᵬஹîÄýḄþÿᙶ᪗Ḅ⊤Ḅᱥᳮᑖ᪆Ḅᜧᐵ(2)᪷ᵬḄᦪᑨᙊḄ!"#(3)᪷$ᑨᙊᙠ&Ḅ!"#'᪷!ᩩ)*+Ḅᜧ(4)᪷ᱥḄ!ᩩ)ᑖ᪆&,-.ᙊ,-Ḅᜧᐵ஺0⚪ὃ34567ஹᱥḄ!ᩩ)Ḅ9ᵨ';<=Ḅᱥᳮ⊤Ḅ>?@A⚪ḄᐵB஺16.ூEᫀ௃ADூA᪆௃AHAஹIJᙠ₩LᓟḄNO'ᙠ6ḄPᔣRSN4TU'6VWX4Y'ᦑA[<\IJᙠ₩LᓟḄNO']-ᜧ\^Pᔣ_`aᦋc'ᡠ\eḄfgh᝱ᦋc4'ᦑ8┯kCஹIJᙠᔣRl]fgḄNO'm6nLᓟḄo'ᦑC┯k஺ஹIJᙠ₩LᓟḄNO'eᡠm6ḄPᔣpqrsᔣt'ᦑ஺[<஺ᦑ⌱HAD.(1)XYḄvwx⌕z{H|@}ᵨᙠᱥRḄ'~@ᱥᙠḄPᔣRSNḄTU(ᓽnTUḄPᔣ⌕|)~ὅ|(2)ᱥᢝ☟ᡈᒴ]sfgh᝱'fgh᝱c]-ᜧᡈfgPᔣ`aᦋc'ᡃᱥḄfgh᝱`a4ᦋc(3)IJm6nLᓟḄo(4)6ḄPᔣ@rsᔣtḄ஺0⚪ὃ34Yஹfgh᝱ḄᑨஹmḄᑖ᪆\^6PᔣḄᑨ'Ạ஺17.ூEᫀ௃CDூA᪆௃AH4ஹᑜ᫔Vᨵᔣ¡Ḅ}ᵨ'ᵫḄ}ᵨ@£¤Ḅ'¥V᫔¦ᨵᔣ§Ḅ}ᵨ'[@V᫔ᔣ§Ḅ}ᵨ¨Ḅfgh᝱`a4ᦋc'ᦑA┯k©26⚓'ᐳ40⚓

268ஹ®ᜐ°@z±mᑮ6Ḅ³z'ᦑB┯k;Cஹµᙠ☢R'ᵫµᩩ)/=6ᱥ'¹ᜧºn»¼Ḅ6'½»¼¾¿'mḄ¦cᜧ'ᦑC[<஺ஹ&ÀÁÂḼÄ-Ḅ¾¿Å¾ᜧ'ᦑ஺[<ᦑ⌱HCD.(1)ᑨ+Æ@Çᱥ'Æ@mᱥÈᔠḄ}ᵨ@£¤ḄÊᑨËÌᦋc4ÍḄfgh᝱(2)Îឋ@'®ᜐ°@mᑮ46Ḅ}ᵨ(3)@µᙠ☢RḄ'ᵫ~Ð⊝ᜧº6ᜧ(4)᪷&ÀÁḄÒÓP=pghᑨ஺0⚪ᐹᨵ|ḄÕᔠឋ'Ö6ᱥᳮna×Ḅὶ'ὃḄÙÚ஺18.ூEᫀ௃DூA᪆௃AH4ÛᳫfgᕒÞßà(SNÞßá᦮WḄfgã᝱)näåà(ᵨᩭäå)Ḅçèᩞᧇ¥'ëì☢íîO-¥'@±4ï*¥ᜧḄ᥅ñ'ᦑA[<8ஹßòmᑮóḄ}ᵨ'ôõᙠóḄPᔣRSN4TU'ᡠ\X4Y'ᦑB[<Cஹßòöó+¡÷ᔣ§äåḄNO◤⌕ùúûüýn᥅ñýXY'|þᑖÿ
ᓄᑁ
ᡠᐸ
ᦑC஺ஹ⚞ᳫᕒᑵ!"ᡠ#᥅%&'"Ḅ)Ḅ*᠒ᦑ஺┯-஺ᦑ⌱/D஺(1)0ᜧ᥅%Ḅ23/ᙠ5&670ᜧ89☢Ḅ;<=)஺ᙠ89☢Ḅ;<=)670ᜧ5&(2)✌ᐜ᪷ABCḄDEF⌕HIᑖ᪆LMᔜOPQᕒR"SᔲBC(3)UVWX&Y᥅%X&
Zᨵᓄᑁ

\ឤ஺Aᑖ᪆ᑨ"Ḅ
_ᓄ(4)᥅%Ḅ23/5&ஹ89☢Ḅ;<=)ஹ`QabcQஹ'89☢def஺⚪S&hijḄkᔠmᵨo⚪᪷AᡠhḄᱥᳮij⌲E᣸◀u)ᜧ஺

2719.ூyᫀ௃ACூo᪆௃o:ABஹᵫᱥᙠᵬஹMᡠ=Gᱥ,FzP8,ᓽp/>PzSDḄ)iᦑ᪷AP=Pgi3¡¢£ᘤ¥#ᑮ5§Ḅᜧᐵ©ᦑcஹ஺┯-஺ᦑ⌱/AC.(1)᪷AᱥḄᩩ¯ᓽᑨ&ᜧ/ᙠ☢Ḅᱥ#ᑮḄ&°±Ḅ²&ᙠ¥³Ḅᱥ#ᑮḄ&±Ḅ²&(2)᪷AᱥḄµ¶ᑨ¢ᱥ·)¸·)Ḅᐵ©¡ᑮD¹·)ᐵ©SDḄ)iᦑ᪷Ap=pdg"i3¡¢£ᘤ¥#ᑮ5§Ḅᜧᐵ©஺»⚪¼⌕ὃ¾ᱥᩩ¯Ḅmᵨ¿᪷AᱥᙠMḄÀ᝱7ᱥ#ᑮḄ&¸ᱥ²&Ḅᐵ©ÂᱥḄ·)¸·)Ḅᜧᐵ©/ÃᐭMḄᱥÅᱥÆÇᑣPᱥ

28ᨬ@ᑭᵨF=tt“#+G)%&ḄD<)(3)᪷0E&ᱥBᙠ2sᑁḄ᪷0!"#$%&ᱥB4ᓣḄ!"HIJ7&1ᵫ2Ḅ!")ᙠKLMNᓣᱥḄOPQᔁS;<ᔆḄ᳛UᢝWXᑭᵨP=&="=Fu%ttᓣᱥBZḄ;<ᯠ@ᑭᵨF=|(G+G)%ᱥB\ᑮḄD<)᪷0^ᨵ=Gh%B&_ᱥB`Ḅᨵᵨ)(4)᪷0ab=3%&c8᪷0d=/x100%%&ᦔ᳛஺f⚪ὃijkᵨZᨵᵨஹcஹ᳛ஹᦔ᳛ḄmnᐵpqrQE&ᨵᵨstmnZuvᓫxyIz{|⚪஺21.ூᫀ௃
D<Ḅᔣ'(ᔣḄODIᩩᜮḄ'(ᔣḄᨵᔣᵨG⊤᝞ᡠ

29ூ᪆௃᪷0D<Ḅᔣ'(ᔣḄOD`'(ᔣḄ<ᓽ஺f⚪ὃijD<ḄvḄ.Wᱥ᪵D<Ḅᔣc'(ᔣḄ஺22.ூᫀ௃0Aூ᪆௃
Q0Arᑮ<ḄᵨᔆḄACL0B,0BᩨᩚW<Ḅᵨᡠ¤0A<¥.ᦑᫀ3
04⌕¨©⚪◤⌕«¬<¥Ḅᭆ®⍝<¥rᑮ<ḄᵨḄ.ὃi°±_<¥Ḅᭆ®Ḅᳮᐵp⍝<¥rᑮ<ḄᵨḄ³Ạ⚪µ.23.ூᫀ௃·<¸⊝2.8»ᨵ¼ᑴ¾<ᜧ>WXூ᪆௃
(1)ᵨÁÂÃÏ{;<)ᵫÃäåᩈᙽæ'(ᔣçèIé”ᩈᙽ_ÙÚ☢Ḅ¾<Õë±jXᓄᦑíᙠÖ×OPQîᙠḄï⚪»ᨵ¼ᑴ¾ðñÖ×᥅Î<Ḅᜧ>ØÙÚ☢Üᔲᨵᐵ⌕¼ᑴ¾<ᜧ>ÌÙÚ☢ḄßàP"WXóᦋXÙÚ☢Üᜧ>õmḄö÷Jø
ù30⚓ᐳ40⚓

30জÇᩈᙽ¸ýᙠÇᩈþ4ᵨÁÂÃ

31RSᦋS³»pᦑ%&ãÌÍ2ஹ5ᡈ4ஹ6Ḅ·ä\]ᦪᓽØ!(4)ᵫç³ᑁÜḄQ¬8¡p`ᡂ©%Ḅ³Q¬8¡pḄ%q`}¢Ḅ;p—800a஺ᦑAᫀCD(1)!(2)~:¡p!}¢!(3)2ஹ5ᡈ4ஹ6!(4)800o(1)Q¬³Q¬Ä`gh°±²ᩭêÎQ¬Ḅgh°ë¶Q¬ḄSᓄᩭᦋSUµ¶³☢Èp¾Ḅº³Q¬஺µ¶Ḅ³☢ÄRÅSᓄ;(2)ᙠ³ᑁÜḄ~Ú¡p³ᔣᔜÞᔣḄQ¬}¢!(3)⌕vw³ᑁÜQ¬Ḅᜧ.ì³Ḅ»pḄᐵx◤⌕Oᑴ¡p}~ᦋS³Ḅ»p!(4)¹³Ḅ»p`íîãÆ/0³ᑁÜḄQ¬8¡p`ᡂ©%Ḅ⌕ï³8cm¡ᜐḄQ¬Øñᙠãòó⌱õÚÞ³8c,”¡ᜐḄQ¬Cp,ᑭᵨQ¬8¡pḄ%q`}¢Ḅö÷¢øùᐭᦪqïu஻Ḅᜧ.஺⚪vw³Q¬ᜧ.ḄὃüᣚஹOᑴSþp=pg/iḄᵨ஺25.ூAᫀ௃4}~}~ÿ
ᢝᒴ᝱ூ᪆௃(1)ஹᑮᩈ☢!"#$%&'Ẇ)*+,ᱥ.Ḅ01⌕ᙠ&'Ḅ4Ạ67ᳮ9:ᱥ.;<+=Ḅ᝱ᦑ☢,$?Ḅ*+@⌲B#$CDᙠEFG☢6HI&'ᩞᧇḄLM@Nஹஹᩈ஺ᦑ⌱AQ(2)Ẇ)“*+,ᱥ.Ḅ01”TUḄHIᩞᧇᑖWNஹஹᩈXYZ$?[\ᑮ]EF☢Ḅ"^_@`$?a☢Ḅ^_ḄbcᵫefQᙠEFG☢6HI&'ᩞᧇḄLM@NஹஹᩈgNXYᙠD&'Ḅ4Ạ6hijkl7ᳮ9:Ḅᱥ.;<+mᵨ=
ᢝᒴ᝱஺ᦑoᫀX(1)4(2)^_Q^_bQ
ᢝᒴ᝱஺q32⚓ᐳ40⚓

32(1)᪷v&'wḄxᔠ%⚪{ᵨḄ&'7ᳮ|ᑖ᪆Q(2)&'wḄNẆ)*+,ᱥ.Ḅ01◤⌕~ᑴ$?Ḅ"⌕^_Q᪷vḄᓄXYZ$?ᑮ]EF☢Ḅ"^_@`$?a☢Ḅ_i"cᵫefQ᪷vqio஺%⚪Ẇ)*+,ᱥ.Ḅ01ὃ&'m&'7ᳮ|Ḅᵨ஺26.ூoᫀ௃EFB஺ூ᪆௃(1)ᵫᡠᩨᩚe@ᔣ⁚F⊝¡ZᩨᩚᙠEFbF⊝஺(2)¢ᩨᩚ[i£Ḅ¤"XL,[¥¦ṹḄ¨+XGQAஹᵫ2ᡠ=3Gx3Z,=9GL,=2Gx4L=8GL,ு$«¬®ᩨᩚ;F⊝¯eᦑA┯±QBஹ²¯¦ṹ³ᔣ´µ¶i£=3Gx2L=6GL,=2Gx3L=6GL,=ᩨᩚ·F⊝ᦑ8¸¹QCஹ᝞»ᙠ¯¦ṹe¼½i¥¦ṹ=3Gx3L=9GL,=3Gx4L=12GL,(ᩨᩚ¯eᩨᩚ;F⊝ᦑC┯±Q஺ஹ¾e¯¦ṹᙠ´µ¯¿¥bᵨÀÁÂ+ÃÄ6ÅÆÅ+ÇÅ+Ḅ+ÈḄÉÊËÌ9GL=ᩨᩚÍ·F⊝ᦑ஺¸¹QᦑoᫀX(1)QEFQ(2)BQD஺(1)&'Î@⁚ᩨᩚᙠEFbF⊝᝞»ᩨᩚe@ᔣ⁚F⊝¡᝞»ᩨᩚe@ᔣ⁚F⊝¡஺(2)ᵫᩨᩚF⊝ᩩÐᑖ᪆o⚪஺%⚪ὃYᩨᩚḄ⁚ÇᩨᩚF⊝ᩩÐḄ@ᵨÑ";ᜧᑖ᪆ÓÔஹ@ᵨᩨᩚF⊝ᩩÐᓽ¸¹⚪஺27•ூoᫀ௃×ØḄÙ◍!"ᙠÛ+^_=<+☢ÊÜ$Û+Ḅmᵨᦔ»ÜÞßூ᪆௃(1)&'à
$áâãᙠ×Ø6Näåæç×ØḄÙ◍!"ᩭéêÛ+mᵨᦔ»Ḅß℉!"Ḅ(2)éêìஹí²Û+Ḅᜧ$^_<+☢Ê;_Û+Ḅmᵨᦔ»Þß;_

33ᦑ9xîᙠÛ+^_=<+☢ÊÜ$Û+Ḅmᵨᦔ»ÜÞß஺ᦑoᫀX(1)×ØḄÙ◍!"Q(2)ᙠÛ+^_=<+☢ïÜ$Û+Ḅmᵨᦔ»ÜÞß஺01Û+mᵨᦔ»ḄCðᨵ²¥iNÛ+Ḅᜧ$òN<+☢ÊḄᜧ$஺ᙠ&'à,ôNäåᣚ|Ç~ᑴ#ö|ᩭ,g²¥CðḄ01ᦔ»ᩭh÷ø)Ḅ஺ᙠ%&'àᣚ|Ç~ᑴ#ö|ḄᔠᳮᵨNᡂúḄᐵüᣚ|ôNýÛ+Ḅmᵨᦔ»ᣚX×ØḄÙ◍!"h÷æç~ᑴ#ö|ôN
Û+ᜧ$<+☢Êᜧ$²¥Cðh÷ᑖWø)஺28.ூoᫀ௃20.2488.9%¼ᜧᱥ.Ḅ¨+ᡈᣚᵨÿḄ
ᡈᣚᡂḄூ᪆௃(1)
Ḅᦪn===3,᜻ᦪ
ᢞ!"#$᝞&'(2)(1)*+Ḅ,-:w᝼1=F1S1=0.95/Vx0.33m=0.3135/.0ᨵᵨ᪷4஻=6X100%7(1)ᨵᵨ-“,Wᨵᵨ*=W,/=0.3135/X70.2%=0.220077:,ᵫWộ=G/i=>(1)*+Ḅᱥ@AB=C0=2.0007…N:1hi0.11m(2)*+Ḅᨵᵨ-W@ᵨ2—Gh-2Nx0.12m=0.24/:22(3)*+ḄDEᦔ᳛=HX100%=Ix100%=Jx100%X88.9%:'JWF3s30.75NX0.37n;(34⚓ᐳ40⚓

34(3)ᵫ⊤Pᦪ47)ḄDEᦔ᳛#$ḄᩞRᨵᐵஹᱥUḄ@Vᨵᐵஹ
Ḅ@VᨵᐵW$Xஹ
XஹᱥUX@DEᦔ᳛XYᡠ[\⌕^Y_)ḄDEᦔ᳛*+`aḄbcdefgᜧᱥUḄ@VᡈᣚᵨḄ
ᡈᣚᡂḄ஺ᦑkᫀ(1)no':(2)2:0.24:88.9%:(3)gᜧᱥUḄ@VᡈᣚᵨḄ
ᡈᣚᡂḄ஺(1)ṹoᓣḄYy6,|$}ᵫ~
ḄS,ḄᐵfS=nh,ᑣ=,஻
Ḅᦪᯠ᪷4“᜻
Ꮤ”Ḅᑣ!"#$:(2)᪷4“,=Fs=>(1)*+Ḅ,-᪷4஻=100%=>ᨵᵨ-ᵫ“ᵨGh=>(1)*+Ḅᱥ@:᪷4ᨵ=6/1=>(2)*+Ḅᨵᵨ-:᪷44=x100%=x100%(3)*+ḄDEᦔ᳛:W&FS(3)᪷4)DEᦔ᳛Ḅ¡^>^Y)ᦔ᳛Ḅde஺¢⚪ὃ¥¦)Ḅ#eஹ*+ᦪ4ᑖ᪆¨ᵨ©ᑴ«¬eᑖ᪆⊤`*+ᦪ4ஹ¨ᵨᦔ᳛®ᓽ°±⚪஺29.ூkᫀ௃Cூ᪆௃4²ᢄᓱᱏᙠ·¸¹ᢞº6ṹ»²¼½VḄᜧ¾¿À·¸Vᜧ¿Á⊝+ÃVÁ⊝VḄᜧ¾ḄᐵᦑA┯Æ:8.²ᢄᓱᱏÇᐸÉÊᔣ&
ºÌ¼VḄdᔣ¿ᙠÀºÊ$odᔣÍ¿ÎÏᨵ©ᑴЫ¬ᦑB┯Æ:C²ᢄᓱᱏ#ᐸ`ÓᙠÉÊÁ☢ÕÖ90஺½6V¿ᙠÀºÊ$o»²¾ᓱᱏ¿Á⊝×ØÖ
ᨬ¾ᓱᱏ☟Û¼½6VÜᜐÞÀºÊ$o:ᡠ[ß6bcfàáâÁ⊝Ḅ½6VfᔲäåᜐÞÀºÊ$oᦑC°±:D²ᢄᓱᱏ·¸ÉÊᔣo
ºÌḄçèéᯠ¿êYëfì½6Vᜧ¾êdᔣÎífcᵨᙠÀºÊ$ocᵨᙠÀº6ᱥUo¾ᓱᱏífᜐÞ☟Ûî᝱¿+ý6VíäåcᵨᙠÀºᩩÊ$oñHÁ⊝ᦑ஺┯Æ஺ᦑkᫀC¾ᓱᱏÖòº6óy¾ᓱᱏoôᑮḄ½6öV÷¿ᙠºᩩÊ$of+ÿᙠÀºÊ

35$o½6VfᔲÁ⊝஺⚪f“àáVÁ⊝ᩩø”Ḅ*+ὃ¥¦VÁ⊝ᩩøḄàáde°±ᳮVÁ⊝ᩩøúᵨ©ᑴ«¬eûaàáf⚪Ḅᐵü஺30.ூkᫀ௃êÞ¾Þூ᪆௃(1)ᵫ'ᵬ7ᙠþÿ
ḄᦪᱏᱥḄᓽᱥᡠG=1.5N,ᵫ!2ᱥᙠ$%Ḅ&ᦪA0.7N,ᑣᱥᡠḄ()F=G-F2=1.5/V-0.7N=0.8/V/ᵫ0F33᫜5ᱥ᣸7$ᡠḄ81.2N,ᵫ9:3᫜ᡠḄ0.4N,ᑣᱥ᣸7$ᡠḄ)G//=!3—==12N-0.4N=0.8N/(2)ᵫ@☢ḄBCD5EFGHᱥᡠ(ᜧ3ᱥ᣸7JḄ/(3)Kᢞᙠ
MḄᱥᙠNᨵPQR$SḄ$☢TUR$SNᨵVW$ᱥ᣸7Ḅ$XYᐰ[\ᐭ3᫜^_G᣸`3ᦑ᣸7$Ḅ3ᱥᑮḄ(஺ᦑdᫀ)(1)3᫜5ᱥᱥᙠ$ᱥ᣸7$ᱥᡠᱥᡠ(᣸7$ᡠ3᫜ᡠḄFᦪ%ḄᡠḄ/N/NḄ8/N&ᦪ/N/N/N11.50.70.81.20.40.8...(2)/(3)3஺(1)᪷hᦪḄiᓄkl(5᣸7Ḅ$Ḅ/(2)᪷h(5᣸7Ḅ$Ḅᑖ᪆/(3)KR$SNᨵoW$ᱥ᣸7Ḅ$Nᨵᐰ[Rlhpᑖ᪆ᱥ᣸7$ḄqᱥᑮḄ(Ḅᐵs஺p⚪ὃvwxyz{ᳮḄGH}~ᑖ᪆GHᦪhḄᑖ᪆Y⍝⚪஺36⚓ᐳ40⚓

3631.ூdᫀ௃ṹXPQ$☢G-FCூ᪆௃)1GH)জ
/
56ṹ᝞ᡠPMᱥG,ᐭ⊤/ঝᙠᛛᧇᜧ¢ᝰoᐭ〉¥Ḅ$$☢¦6ṹᢞᙠ§%Ḅ¦¨஺©6ṹḄṹªNᙠᛛᧇᜧ¢SḄ$«¬ṹXPQ$☢Mp%Uᯠ«¯%Mp%
Ḅᦪ/ᢗᐭ⊤/ঞ⌲³´µªᐭ$Ḅṹᦪ¶᯿ঝ¸¹5FᑖºM»¼Ḅᱥᳮ¥«ᐭ⊤/ট᪷h¾¿FÀ=G-FÁBlÂFGHṹᡠḄ(ᐭ⊤஺2GHᦪhÃ⊤)123456ṹG/N᣸7JḄÄÅ/Æ3Ç!ᢈ/N(!(/Nᦑdᫀ)1জ/ঝṹXPQ$☢)টG-F2@⊤஺}~ᱥᙠ$ᡠḄ(Ḅᜧ3q᣸7$ḄÄᡂÊ˼ÌᑴJḄΨXiᦋiᱥ᣸7ḄJḄÄ஺p⚪ÐÑ©Ò:ÓGH}~(ᜧ3q᣸7JTÔḄᐵsὃvḄÒ:ÓGHÕᫀḄY⌕kÒ:×ØḄÙÚ(¥ḄÕÛÜÛ/(=G-!ᡃḄᨵᐵÞ஺32.ூdᫀ௃஺30᣸l$ßᑁḄ$`3áâ^ã‷åæ@(çឋ400

37ூ᪆௃)(1)᪷h“êëì”îïê$ðñ@ñΨᜧஹMñΨ3,ópᵫôF=pgõêëìḄê$Ψiᓄö⌼ᡂã‷ᑮḄ(`3ã‷ḄXiø(3%ã$‷öMùᦑ஺Êú/(2)ø/i=300m%ã‷ᑮḄûü)p=pgh=1.0x103kg/m3xION/kgx300m=3.0X106Pa/ê$Ḅûü᪗þᜧÿḄᦪn==30(3)‷ᙠᵫḄ☠Ḅᦋᩭ!Ḅ“ᔣᡠᨵḄ&'()”Ḅ+Ḅ᣸-&'ᑁḄ&/01/2‷34(4)56()ஹᐵ9ᔜ;▀=>/‷ᣵ@ᨵᡠ0AᵫB‷ᐹᨵDឋ/⌕GHIᢝKᩭḄLMN᝱/ᡠPQRSᓽUV஺(5)&‷ᐭ&YZ[ᑮḄ?'=PD9E᣸=PDgVFD‷=1஺xlOikg/m3xION/kgx3x1037n3=3x107/V⌕2&‷/GFD‷*G_NF'/ᡠPab⌕ᔣ&‧ᐙᐭ&ḄGD=F/-GFD‷=3X107/V-2.6x107N=4x106JV,᪷fG=mgp=/gh/ab⌕ᔣ&‧ᐙᐭ&Ḅijᓃ=&=_____no_____=400m3_pDgl.Ox103kg/m3xION/kg°ᦑqᫀ(1)஺(2)30(3)᣸-&'ᑁḄ&/01/2‷34(4)Dឋ(5)400஺(1)᪷f᝞u&vwwxyᜧஹwxy1ḄN᝱/{ᡂ}xy~yvw/“Y”஺ᔠ=P9%gh-(2)᪷fp=pgh-iḄᜧ1/ᯠ>ᜧ)(3)&'᣸&/‷h⚜ᜓ/Z‷ᑮ☢஺&'ᐭ&/‷ᜫ⚜ᜓ/Z‷ᑮ&(4)ᱥiᨵIᢝKᨵLMN᝱QḄឋ/;ឋDឋ஺ᑗᱥi¡ᨵDឋ(5)¢⍝&‷Ḅij/ᑭᵨ¦§¨©Kᳮg&‷ᐭ&Y[ᑮḄ«'/⌕2&‷/&‷Ḅ(&‷¬&ᑁ&)ᜧB[ᑮḄ/f-ᙠ&ᑁab¬Ḅ&¯ᑭᵨG=mgP=ⅉ±²&Ḅij஺³38⚓/ᐳ40⚓

38⚪·ᔠὃ¹º¦§¨©KᳮḄ»ᵨஹiஹᱥi¼ᩩ¾Ḅ»ᵨ¿Dឋ¢ÀÁ¢ÀÃ/⍝·ᔠឋÄḄ⚪+/ᐵÅÆÇ▅Éᩞᧇ/ᳮÌÍᐵ¢À஺33.ூqᫀ௃Ì(1)&ÓḄp=pDgh=1.0x103kg/m3xION/kgx0.1m=lOOOPa(2)ᵫp=5gh&ÓḄF=pS=lOOOPax50x10—2=(3)1ᳫ᣸à&Ḅijá=%=IL/,1ᳫ[ᑮḄF=PDgv᣸=1.0x103kg/m3xION/kgx10_43=INm(4)è1ᳫ☟V/1ᳫ[ᑮêëᔣḄì¬B1ᳫḄ/1ᳫḄGA=«+Fᶯ=IN+3N=4N஺q(1)&ÓḄ1000P«(2)&ÓḄ5N(3)1ᳫAᙠó&ÓY[ᑮḄIN#(4)1ᳫAḄ4N஺ூÌ᪆௃(1)¢⍝ó&Óᑁ&@/ᑭᵨp=pg/i&ÓḄ(2)¢⍝ó&Ó☢j/ᑭᵨp=(&ÓḄ(3)1ᳫ᣸à&ḄijBó-&Ḅij/ᑭᵨ¦§¨©Kᳮ1ᳫ[ᑮḄ(4)ᵫB1ᳫ☟V/1ᳫ[ᑮêëᔣḄì¬B1ᳫḄ/f1ᳫḄ஺÷⚪ὃ¹ºiøùஹúûùஹ¦§¨©KᳮḄ»ᵨ/ᐵÅ¢⍝1ᳫüᐰþÿᙠ
᣸
Ḅ
Ḅ஺

3934.ூᫀ௃(1)Ḅᨵᦔᦪn=2,ᑣḄ#$ᦔ᳛n=—x100%=—x100%=—x100%=—x100%=—x100%=90%,1w..,FsFnhnF2F&'()=500N+(2)ᔁ-#'Ḅ./uL=nvᱥ=2x0.2m/s=0.4m/s,'()01Ḅ1᳛%Fsp=Y=?=FuL=SOONxOAm/s=2001V;(3)23456Ḅ᥅8ᵫF=+(G+G);&ᡠ=Ḅ4(G=nF-G=2x500/V-900/V=100N஺o(1)'(/?500N+(2)'(F01Ḅ1᳛P?200W+(3)ᡠ=Ḅ4(Go?100N஺ூ᪆௃পḄᨵᦔᦪn=2,᪷C4=Dx100%=,x100%=Ex100%=2x100%⊤GḄ#$ᦔ᳛ᓽ;I'(F+(2)᪷C?=JᱥIᔁ-#'Ḅ./ᑭᵨP=7=7=F"I'()01Ḅ1᳛(3)23456Ḅ᥅8᪷C)=+(G+G)Iᡠ=Ḅ4(஺N⚪ὃQR#$ᦔ᳛ST51᳛STஹ'(STḄVᵨ⌕XYᔁ-#'Ḅ./Z[\ᩞᧇA_ᓣ./Ḅ2a஺b40⚓ᐳ40⚓