等效的思维方法就是在保证效果相同的前提下,把陌生的、复杂的物理现象变换成熟悉的、简单的物理问题的方法。作为一种科学的思维方法,在物理学中有着广泛的应用。1.按物理原理进行等效变换〔例1〕如图1所示,质量为2kg的物体受到5个力的作用而处于静止状态,若将10N的力F1撤去, The equivalent way of thinking is to transform unfamiliar and complex physical phenomena into familiar and simple physical problems under the same guarantee effect. As a scientific method of thinking, it has a wide range of applications in physics. 1. Equivalent transformation according to physical principles [Example 1] As shown in Fig. 1, an object with a mass of 2 kg is subjected to 5 forces and stands still. If the force F1 of 10 N is removed,