如图所示,在边长为a的正六面体的棱边CD上,作用着与其重合的力F,则力F对x、y、z轴的矩为[img=351x334]17de8f8200fff66.png[/img]
A: Mx(F)= -Fa, My(F)=Fa, Mz(F)=0
B: Mx(F)=0 My(F)=0 Mz(F)=Fa
C: Mx(F)=Fa My(F)= -Fa Mz(F)=0
D: Mx(F)=0 My(F)=0 Mz(F)=0
A: Mx(F)= -Fa, My(F)=Fa, Mz(F)=0
B: Mx(F)=0 My(F)=0 Mz(F)=Fa
C: Mx(F)=Fa My(F)= -Fa Mz(F)=0
D: Mx(F)=0 My(F)=0 Mz(F)=0
举一反三
- 图示力F的作用线在OABC平面内,此力对各坐标轴之矩为()。[img=566x480]17e0ba674f72d05.png[/img] A: Mx(F)≠0,My(F)≠0,Mz(F)≠0 B: Mx(F)≠0,My(F)≠0,Mz(F)=0 C: Mx(F)≠0,My(F)=0,Mz(F)=0 D: Mx(F)=0,My(F)=0,Mz(F)=0
- 若一个空间力与x轴相交,但不与y轴、z轴平行和相交,则它对三个坐标轴之矩应是()。 A: Mx(F)≠0、My(F)≠0、Mz(F)≠0 B: Mx(F)=0、My(F)≠0、Mz(F)≠0 C: Mx(F)=0、My(F)=0、Mz(F)≠0 D: Mx(F)=0、My(F)≠0、Mz(F)=0
- 一力F作用在平面OABC上(如图所示),于是力F对OX、OY、OZ三轴之矩应为()。 A: mx(F)=0,my(F)=0,mz(F)=0 B: mx(F)=0,my(F)=0,mz(F)≠0 C: mx(F)≠0,my(F)≠0,mz(F)=0 D: mx(F)≠0,my(F)≠0,mz(F)≠0
- 若已知力F对直角坐标系原点O的力矩矢的大小∣MO(F)∣,方向沿Oy向,则此力对此坐标系中各轴的矩为()。 A: Mx(F)=0, My(F)=0,Mz(F)=0 B: Mx(F)=0,M y(F)= ∣MO(F)∣,Mz(F) =∣MO (F)∣ C: Mx(F)=0,My(F)= ∣MO(F)∣,MZ(F)=0 D: Mx(F)=0,My(F)=0, Mz(F)= ∣MO(F)∣
- 图示力F对各坐标轴之矩为( )。[img=308x273]1803c3479387f13.jpg[/img] A: My(F)=0,其余不为零 B: Mx(F)=0,My(F)=0,Mz(F)=0 C: Mz(F)=0,其余不为零 D: Mx(F)=0,其余不为零