问题:
如图所示,物体A重100N,B重20N,当B匀速下降40cm时, A受到桌面的摩擦力和A移动的距离分别是
[ ]
A.20N,40cm
B.10N,20cm
C.10N,80cm
D.20N,20cm
如图所示,物体A重100N,B重20N,当B匀速下降40cm时, A受到桌面的摩擦力和A移动的距离分别是
B.10N,20cm
C.10N,80cm
D.20N,20cm
[ ]
A.20N,40cm B.10N,20cm
C.10N,80cm
D.20N,20cm
参考答案: