ʱ : (课标通用)甘肃?019年中考物理总复?阶段检??简单机械和功、热和能试题 - 百度文库ϿʼĶ
μ() еȺ
(ʱ:60 :100)
һѡ(ÿС3,21)
1.ͼʾֻеͬһ,ƻеغĦ,ʡ( )
:D
:ѡAжС,Ƿܸ;ѡBǵȱ۸ܸ,ʡ;ѡCеֵΪ2,Ϊص2;ѡDеֵΪ3,Ϊص3,ʡ,ѡDȷ 2.
1
1
ͼʾ,300 NΪ500 N10 s2 m,غĦ,ڴ˹( )
A.ɶƶľΪ6 m B.100 N C.ĹΪ100 W D.ĻеЧΪ60% :B
:ͼ֪,n=2,ɶƶľs=nh=22m=4m,ѡA;غĦ,F=??(G+G)ɵ,ֵΪG=nF-G=2300N-500N=100N,ѡBȷ;ɶƶٶv=??=10s=0.4m/s,P=Fv=300N0.4m/s=120W,ѡC;=??500N
1
??4m
??
=????=??2??=2??=
??????????2300N
83.3%,ѡD
3.
1
бϽһΪ5 kgߴ,ͼʾ,бϵΪ40 N,б泤2 m1 m,ֱhĹΪù(gȡ10 N/kg),˵ȷ( ) A.ֻĦ B.ù50 J C.бĻеЧΪ83.3% D.ܵĦСΪ10 N :B
:бʱ,֧Ħĸ,ѡA;ùW=Gh=mgh=5kg10N/kg1m=50J,ѡBȷ;FܹW
??
=Fs=40N2m=80J,бĻеЧΪ=??100%=80J100%=62.5%,ѡC;˷Ħ
ĶW=W-W=80J-50J=30J,W=fsɵ,ܵĦf=??=D
4.αСʵ顪ֽˮ,ʢˮֽڻ,ˮտֽԲȼ,Ϊ
A.ֽıݴˮı,ֽȼ B.¶Ƚϵ,ֽŻ C.ˮտ¶ȱֲҵֽŻ D.ֽ,ֽȼ :C
:ڱѹ,ˮķе100,ˮ¶ȴﵽ100ʱ,¶ȱ100治,ûдﵽֽŻ,,ֽװˮھƾƻ,ˮտ, 5.ͼʾijۻ¶ʱ仯ͼ,ͼ֪,( )
( )
??
30J2m
50J
=15N,ѡ
A.Ǿ,۵0
B.Һ̬ıݱȹ̬ıС C.ڵ4 minʱ,ûгҺ̬
D.ڵ2 min6 minܲ :A
?ѧ77164145?
2
:ͼͼǾۻ,֪þ۵Ϊ0,ѡAȷ;2ӿʼۻ,6ۻ,ڵ4minʱ,ʴڹҺ,¶ȱֲ,ܲ,ѡCD;ͼ֪ʴڹ̬ʱͬ¶յҺ̬ʱ,ԸҺ̬ıݱȹ̬ıݴ,B
6.ܷ仯( ) A.ˮƽĵ B. C.ˮƽе߳ D.ֹϵĿα :B
7.ʵ,ȴݵķʽıܵ A.ˮů,ֵ¶ B.þľ,¶ C.Ħ,ֵ¶
D.ַ˿,۴˿¶ :A
(ÿ2,18)
8.²̼άиǿȡȡܶС,һ̼άС˻,Ϊ2 kg,5 sֱ10 m,˻˷Ϊ J,Ϊ W(gȡ10 N/kg) :200 40
:˻m=2kg,G=mg=2kg10N/kg=20N,˷
( )
W=Fs=Gs=20N10m=200J;
P==
????200J5s
=40W
9.dzһ,:ʢСϵʢˮ֮,ٷŵ,Ϊ˱ּԭ֭ԭζ,Ҫͨм콫졣֭ (̬仯)γɵ,,ŵŨζ,һ :Һ ɢ
10.2017518,ҹϺȼԲɳɹ,ȼΪԴ,žĿʹDZͬ,ȼȫȼշųﵽúʮ,˵ȼ ܴ,10ĹϵԼ,1 kgȼȫȼշųΪ J(qú=4.210 J/kg) :ֵ 4.210
:(1)ͬ,ͬ,ȼȫȼշųﵽúʮ,˵ȼֵܴ;(2)1kgúȫȼշųQ=mqú
8
7
=1kg4.2107J/kg=4.2107J,1kgȼȫȼշųQ'=Qš10=4.2107J10=4.2108J
3
11.
ߡһֿٵͽ˶ʽ۲·,Խ˵ĽΪһܸ,ͼʾ,ʱ˵Ľǰ֧,ܵ,СȼʩӵǶ֪ij˵Ϊ80 kg,gȡ10 N/kg
(1)뻭СȼʩӵFl1
(2)ͼƬ,Сȼ N
(3)ͨ:Բͬʽͽ˶Сʱ,ڵʾǶȷߡܽԭ:
˶ʽ E/J
ɢ 315 1 165.5
1 260 1 764
:(1)ͼʾ (2)400 (3)˶ٶԽ,ڵλʱĵԽ :(1)OFߵĴ,ôΪF,ͼʾ
(2)˵ΪG=mg=80kg10N/kg=800N;ͼ֪,F۴ԼG۵Ķ,ݸܸ˵ƽ֪F=??????1
=800N=400N ??12
(3)ɱеϢ֪,˶ٶԽ,ڵλʱĵԽࡣ ʶͼͼ(ÿС3,9)
12.ͼʾ,ͼ¶ȼƵʾֱΪ 桢 档
:32 37.3 -10
13.ͼʾͻһѭĸ,˳Ϊ
4