(2)滑動摩擦力f = μ g = 0.5× 0.5× 10N = 2.5N
m f =μmgCO = 2.5×0.2納米= 0.5納米
力矩平衡的M G +M f =M T
拉力t =(mg+MF)/CB =(1+2.5×0.2)/0.3n = 5n。