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]
09.21: A 20.0 kg box remains at rest on a horizocc.:k htug2+ qntal surfaczbrnqw9,v 9-be while a person pushes directly to the right on the bo- nqz9b9 ,vbwrx with a force of 60N. The coefficient of kinetic friction between the box and the surface is $\mu_k$ = 0.20. The coefficient of static friction between the box and the surface is $\mu_s$ = 0.60. What is the magnitude of the force of friction acting on the box during the push?
A. 200N
B. 120N
C. 60N
D. 40N
E. 0N
参考答案: C
本题详细解析:
暂无
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