(1) (2)F压1=P水1SQ=ρ水gh1SQ = 103 kg/m3 ×10 N/kg ×(l -0. 05)m ×0. 01 m2 =95 N F压2 =P水2SQ =ρ水gh2SQ =103 kg/m3 ×10 N/kg x (0. 6 -0. 05)m ×0. 01m2 =55 N. G人 =m人g=54.4 kg×10 N/kg=544 N, ∵ (GQ+ F压1) . OA = FB1 ·OB,(GQ+ F压2). OA = FB2 · OB, ∴FB2= (GQ+F压2)=×(5+55)N=240N ∴FB1=(GQ+F压1)=×(5+95)N=400N 4F1=G0+FB1 ① 4F2=G0+FB2 ② FN1+F1=G人 ③ FN2+F2=G人 ④ 又∵①一②可得:4F1-4F2=FB1- FB2 =400 N -240 N =160 N, ∴F1-F2 =40 N,
∴F2=64N,F1=104N ∴G0=4F1-FB1=4×104N-400N=16N. (3)∴FN1=G人 -F1=544N-104N=440N。 |