人教版义务教育九年级实验教材中的摩擦力是初中物理重点内容之一,是历年来中考必须考查内容之一,是今后学习高中物理的基 The friction in the ninth-grade experimental teaching materials for the compulsory education of the People’s Education Press is one of the key contents of junior high school physics, and it is one of the contents that must be examined in the senior high school entrance examination in the past years. It is the basis for future studies of high school physics.