本题目来源于试卷: Newton’s law of motion，类别为 美国物理杯赛(Physics Bowl)
[单选题]
02.40: A box with a mass of 50 kg is dragged across the floor by a rop xb zahpho -9:bwx6, y4e which 0 g.n-z uafr3v makes an angle of 300 with the horizontal. Which of the following would be closest to the c vf a0rz-n gu.3oefficient of kinetic friction between the box and the floor if a 250 newton force on the rope is required to move the crate at a constant speed of 20 m/s as shown in the diagram?
A. 0.26
B. 0.33
C. 0.44
D. 0.56
E. 0.77
参考答案: D
本题详细解析:
暂无
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