10月考试季终于落下帷幕了，大家觉得此次的题目难吗？今天小编带大家一起来解析一道edexcel M1的真题，来看看此次考试真题究竟是什么水准的？
　　A particle p, of mass km lies on a fixed rough plane. The plane is inclined to the horizontal at an acute angle ａ. A horizontal force of magnitude X acts on P. as shown in Figure 1. The line of action of the force lies in the vertical plane which contains the line of greatest slope of the inclined plane that passes through P. The coefficient of friction between P and the inclined plane is u.
　　When X=mg, the partial P is in equilibrium and on the point of sliding down the plane.
　　Show that u=（k tan a?1）/ k tana Deduce that, when k =1 ,a must be greater than 45这是一道很经典的受力分析的题，同学们要先对particle P进行受力分析，rough plane，particle slide down的趋势，所以受到沿着斜面向上的摩擦力，因为摩擦力是阻碍物体运动的力。
　　a问这种题列两个equation：平行斜面和垂直于斜面
　　平行斜面：X cos a f =W sin a
　　垂直斜面：W cos a X sin a=R
　　b问需要学生扎实的基础知识，能够结合三角函数和代数学分析