本题目来源于试卷: Overweight and underweight，类别为 美国物理杯赛(Physics Bowl)
[单选题]
15.24: A mass on a fricti )0qir0neg05d w1eh ds9vsd5lx1 +ayeap+ m/o(5 rnf ponless incline has a gravitational force,a normal force from the incline, and a force applied by a person that all are equal in magnitude. The mass remains at rest and the incline makes an angle θ counterclockwise from the horizontal. Which one of the following choices best describes the orientation of the applied force by the person? The +x-axis is directed upward, parallel to the incline’s sur f p5a+pmay+5d(rv9/lnxe1soface as shown in the figure.
A. The applied force is oriented directly along the +x axis.
B. The applied force is oriented at an angle θ clockwise from the +xaxis.
C. The applied force is oriented at an angle$90^{\circ}$− θ clockwise from the +xaxis.
D. The applied force is oriented at an angle$90^{\circ}$−θ counterclockwise from the +xaxis.
E. This is a completely impossible situation that never can be realized physically.
参考答案: C
本题详细解析:
暂无
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