本题目来源于试卷: Impulse and momentum，类别为 美国物理杯赛(Physics Bowl)
[单选题]
14.12: A box of mass 5.0 kg is being puj19smnwc:+ hn d.r c(msh*5h ouzno/ ml8ed to the right across a horizontal surface while a constant frictional force of 8.0 N acts on the 58mo* oluzh n/box. At some instant of time, the box has a speed of 4.0 m/s and an acceleration of$3.0\; m/s^{2}$ . What is the magnitude of the net force acting on the box at this instant?
A. 7.0 N
B. 12.0 N
C. 15.0 N
D. 20.0 N
E. 23.0 N
参考答案: C
本题详细解析:
暂无
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