关于汽车牵引力问题许多教师在平常讲解时均有错误:如一辆汽车在平直的公路上匀速行驶,均认为汽车在水平方向受发动机的牵引力F和地面的摩擦力f,且F=f,受力分析如图1(画在其质心处).当然这样分析学生也能接受,不会提出异议.但若将题改成一辆小汽车静止在一长木板上,地面光滑(如 On the issue of vehicle traction, many teachers have mistakes in their usual explanations. For example, if a car runs at a constant speed on a straight highway, it is considered that the car is horizontally affected by the traction F of the engine and the friction of the ground f, and F=f. The force analysis is shown in Figure 1 (at the center of mass). Of course, this analysis student can accept it and will not raise any objection. But if the title is changed to a car that is stationary on a long board, the ground is smooth (such as