模型一如图1甲,在粗糙水平面上放一个三角形木块,质量为M,在ab边放一质量为m的小物块,地面重力加速度为g,则地面对三角形木块的支持力大小为,地面对三角形的摩擦力大小为。方法一:隔离小物块并进行受力分析,如图1乙所示:小物块受三个力的作用,重力mg,三角形木块对小物块斜向上的支持力F′,三角形木块对小物块沿斜面向上的摩擦力f′,把f′分解为水平向右一个分力f′1和竖直向上一个分力f′2,把F′分解为水平向左 Model A, as shown in Figure 1, put a triangular block on the rough level, the mass M, in the ab side put a mass of small pieces of m, the ground acceleration of gravity g, then the ground support for the size of the triangle wood For the ground on the triangular friction size. Method one: Isolate the small pieces and carry out the force analysis, as shown in Figure 1 B: small pieces by the force of three, gravity mg, triangular pieces of wood on the oblique support force F ’, triangular pieces of wood Friction along the slope of the friction f ’, the decomposition of f’ into a horizontal force to the right component f’1 and a component of vertical force f’2, F ’is split into horizontal to the left