本题目来源于试卷: Physics Unit6: Work and Energy，类别为 通用国际物理
[单选题]
An 800-N box is pushed up an in:r25 px8i uakvclined plane. f5,kb 0:7q l :8cbvd77lbyvjiwbh q.aThe plane is 4.0 m long and rises 2 if8cw50bbbkjd7v vb:7qla: y7 q.l,h.0 m. It requires 3200 J of work to get the box to the top of the plane. What was the magnitude of the average friction force on the box?
A. $0 \; N$
B. non-zero, but less than 400 N
C. $400 \; N$
D. greater than 400 N
参考答案: C
本题详细解析:
暂无
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