题目内容
F1=F2=1N,分别作用于上下叠放的物体AB上,且A、B均静止,则AB之间,B与地面间摩擦力大小分别为:
A.1N,0 B.2N,0 C.1N,1N D.2N,1N
A
有两个共点力,F1=2N,F2=4N,F3=5N,它们合力的最大值和最小值分别是多少是 ( )
A.12N, 1N B.11N, 1N
C.12N, 0N D.11N, 0N