NO1静力学习题

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,作业：,NO:1,1,、图没画：,2,、图中的符号与公式不一致；,3,、无计算过程,：,公式答案；,4,、脱离体，没完全脱离开来。,作业中的主要问题：,1,5,计算图中,三个力分别在,、,、,轴上的投影。已知,F,1,=2kN,F,2,=1kN,F,3,=3kN,。,题,1,5,图,5,52,5,4,3,5,F,1,F,2,F,3,O,x,y,z,解,：,1-7,求图示的两个力对,A,的矩之和。,5,12,200N,390N,6m,3m,4m,A,2160N.m,1-8,求图示的三个力对,A,点和,B,点,的矩之和。,B,2m,1.5m,A,30N,30N,10N,1m,1,9,钢缆,中的张力,F,T,=10kN.,。写出该张力,F,T,对,、,、,z,轴的矩及该力对,点的矩（大小和方向）。,题,1,9,图,F,Tx,F,Ty,F,Tz,解,z,2m,F,T,x,y,O,4m,1m,1m,A,B,l,1,B,F,A,O,x,y,z,l,3,l,2,1-10,求力,F,对,O,点的矩的矢量表达式,F,x,F,y,F,z,1-11,。,工人启闭闸门，为了省力，常常用一根杆子插入手轮中，并在杆的一端,C,施力,F,C,能将闸门开启，若不借用杆子直接在,A,B,处施加力偶（,F,F,),问,F,应为多大才能开启闸门？,F,F,F,C,=,200,N,C,A,B,0.6m,0.6m,解,：,1-13,F,O,F,P,B,A,30,F,P,A,B,F,AX,F,A,F,AY,F,B,F,B,F,A,C,F,P,A,B,O,F,C,F,C,A,B,F,A,C,O,F,OX,A,B,F,A,O,F,B,F,OY,B,F,B,F,P1,A,F,P2,F,P1,A,B,F,AY,F,AX,F,AY,F,B,F,P,A,B,C,F,P,A,B,F,AX,F,P,F,P,A,B,C,D,F,P,C,D,F,P,A,B,C,F,B,F,Ax,F,Ay,F,Cx,F,Cy,F,Cx,F,Cy,F,D,F,Ax,F,Ay,F,B,F,D,26,图示混凝土管搁置在倾角为,30,的斜面上，用撑架支承，水泥管子重量,F,Q,=5kN,。设,A,、,B,、,C,处均为铰接，且,AD=DB,，,而,AB,垂直于斜面。撑架自重及,D,、,E,处摩擦不计，求杆,AC,及铰,B,的约束力。,A,B,C,D,E,F,Q,45,30,x,A,B,D,F,A,F,B,F,Q,F,D,y,2-11,图示结构已知,M=1.5kNm,a,=0.3m,。,求铰,A,和,C,的约束反力。,B,B,C,A,2,a,a,M,F,A,F,C,212,滑道摇杆机构受两力偶作用，在图示位置平衡。已知,OO,1,OA,=0.2m,M,1,200,，,求另一力偶矩,M,2,及,O,，,O,1,两处的约束力（摩擦不计）。,A,O,O,1,30,M,1,M,2,O,M,1,A,F,A,O,1,A,O,1,30,M,2,F,A,o,4,3,F,1,F,2,F,M,2,2,1.5,0.5,3-6,3-7,A,B,l/,2,l/,2,F,q,F,A,A,B,l,q,F,B,q,2,A,B,l,q,1,F,A,F,B,F,A,F,B,F,P,M,A,B,3.5m,0.5m,F,Ax,F,Ay,F,B,F,Ax,F,2,F,1,3m,2.5m,C,B,2.5m,q,A,F,Ax,F,Ay,M,A,3-8,3-9,F=,4,kN,M=,6,kNm,A,B,C,4m,4m,F,B,F,Ay,F,Ax,M,A,BC:,整体：,3,12,整体：,DC:,3,13,1m,D,A,B,C,4,m,4,m,F,P,F,Q,1,m,4,m,4,m,解,：,起重机左右轮压分别为,F,轮左,10kN,和,F,轮右,50kN,F,B,F,D,F,A,D,A,B,C,F,轮右,F,轮左,F,A,F,D,F,B,1m,0.5m,2m,1m,A,B,F,q,0,C,D,q,3-14,F,D,F,Ax,F,Ay,F,B,DC,:,整体：,M,Ci,=0,F,ix,=0,M,Ai,=0,M,Bi,=0,3,15,C,A,q=,5kN,/,m,F,A,F,AB,F,Cx,F,Cy,4.5m,4.5m,1.5m,B,C,A,q=,5kN,/,m,F,A,F,B,3-16,ACE,:,整体：,3m,4m,4m,3m,A,B,4kN,E,7kN,C,6kN,4m,4m,3m,3m,H,1,2,3,F,A,F,B,F,3,3m,3m,A,4kN,E,C,6kN,4m,1,2,F,1,F,3,E,F,2,2,结点,E,:,M,Ai,=0,M,Bi,=0,M,Ci,=0,F,i,x,=0,F,i,y,=0,0.8,m,0.6,m,1.5m,A,B,3.4,kN,C,D,3-17,F,CB,C,3.4,kN,F,CD,F,A,F,D,F,BD,B,F,BC,F,BA,F,BD,D,F,D,F,AD,F,DC,求反力：,1.7m,3,18,6m,4m,4m,4m,3m,A,B,G,E,4,kN,C,D,2,kN,1,2,3,I,I,I-I,右侧,:,M,Ci,=0,M,Di,=0,F,i,x,=0,F,By,F,Bx,F,A,整体：,F,yi,=0,M,B i,=0,G,F,3,4kN,F,2,C,2,3,D,F,By,F,Bx,F,1,F,yi,=0,3,19,3m,4m,4m,4m,3m,3m,A,B,G,E,25kN,C,D,H,1,2,3,F,G,E,25kN,F,1,D,H,1,2,3,F,G,F,3,25kN,F,2,H,2,3,F,I,I,II,II,I-I,:,II-II,:,M,Gi,=0,M,Ei,=0,F,i,y,=0,A,C,B,P,4-7,x,z,y,F,A,F,B,F,B,M,yi,=0,M,xi,=0,F,iz,=0,4-9,x,y,z,F,z,F,x,F,y,M,y,M,x,M,z,M,yi,=0,M,xi,=0,F,i,x,=0,F,iy,=0,F,i z,=0,M,zi,=0,q,=2kN/m,F,1,=5kN,F,2,=4kN,4m,2m,4m,0.5,1.5,0.2,0.2,1.1,0.8,x,y,o,4-14,求形心,解：,x,y,z,3,4,1,2,1,o,0.8,2,I,II,III,4-15,