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【单选题】
如图所示,在搬运重物时,下面垫以滚子。已知重物重量为P=10kN,滚子重量P1=P2=0.1kN,半径为r=0.3m,滚子与重物间的滚阻系数为δ1=2mm,与地面间的滚阻系数为δ2=5mm,则拉动重物时水平力F的大小为()。A.
118.3 N
B.
121.4 N
C.
113.6 N
D.
125.0 N
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