解 A Cos 8=1.6R/2R =0.8 →0=37°/R mgsin=mat B at=gain 98×0.6=588m/s2 nng Fcos0+N=mg cos28 F=kx y b R×0.6R N=mgcos28-06mg cos0 N=0.28mg-0.48mg=-0.2mg N=-N=-02mg N 目录结束cosq =1.6R/2R = 0.8 mgsinq =mat at =gsinq = 9.8×0.6=5.88m/s2 Fcosq +N=mg cos2q × R kxb F = mg = 0.6R N=mgcos2q 0.6mg cosq N= 0.28mg 0.48mg = 0.2mg N´ = N = 0.2mg N A B R C q F N mg q q 解： = 0 q 37 目录 结束