第六讲典型例题1,1:2:2;1:1:22,720m/s3,CD4,B5,A6,AD7,B8,AB思维训练1,D2,D3,C4,B5,7.27×10-5,465.3,7.27×10-5,402.9,6,3:2:3,1:1:2,3:2:6,7,188,C9,D10,C11,B12,AC13,AC14,4,8,-4挑战自我1,D2,2π√lsinα/g3,D4,AB5,1600n+400或1600n+1200,2000或2800,3600右6,C7,D8,AC9,A第七讲功典型例题:1,摩擦力做功mglsinΘcosΘ;支持力做功-mglsinΘcosΘ;重力做功02,ACD;3,10J,-8.4J,0J;4,80J,20J;5,732J;思维训练:1,7.6J;2,C;3,16J,-14J,2J;4,32J,-32J,0J;5,A;6,100J;7,45J,0J;8,D9,A;10,D;11,mglsinθcosθ,mgssinθcosθ,0J,0J,0J;12,2000J,-2000J,0J;13,FS(1+cosθ);14,Fh(1/sinα-1/sinβ);15,50J;17,1J,2J,0,.15挑战自我:1,ACD;2,D;3,16J,-16J;4,D;5,C;6,D;7,AD;8,B;第八讲功率典型例题:1,D;2,90J,60W,40W;3,减小,减小;4,12;5,10s,26.7m/s;6,375000w,1450m,15s;思维训练:1,450J,250W,300W;2,12,20;3,匀速,6.75;4,600J,120w,240w;5,3000,45;6,500m;7,A;8,20s,20m/s,15s,9,5s;13,FS(1+cosθ);14,Fh(1/sinα-1/sinβ);15,50J;17,1J,2J,0,.15挑战自我:1,C;8,BC;9,150000N,3000000W,16000m;10,20m/s,12S,20400W;11,12m/s,6s;12,12.5m/s,14s,420000J,43200w13,60000w,5s;14,4000N,48KW,5s第九讲动能、动能定理典型例题1,B;2,A;3,C;4,A;5,Fmg=H+hh;6,μ=0.50思维训练:1,ABC;2,D;3,D;4,ACD;5,A;6,;7,;8,7.75s.挑战自我:1,AD;2,A;3,D;4,D;5,C;6,ACD;7,D;8,C;9,L=mgS0sinα+12mv02μmgcosα10,先以2.5m/s2的加速度做匀加速直线运动,运动0.8m与传送带达到共同速度2m/s后做匀速直线运动。220Jv=√35v0S=Hk第十讲重力势能知识精要1、(1)重力势能.(2)EP=mgh(3)标量;相对;正;负;零;.物体和地球;绝对2、(1)WG=mgh(2)路径;高度差3、减少;增加;变化量、4、(1)弹性势能(2)标量;越大;改变量典型例题:1.D2.D3.C4.D5.D6,D7,AD8,245J9,VB=√5gR思维训练:1.D2.B3.B4.B5.B6.D7,20J,24.5m/s,1.2J自我测试1.BD2.A3.ACD4.A5.A6.D7.3m/s8,v=√8gL11,l(1+sin16°),vm=√4gL11;9.vA=25√15gLvB=15√15gL