两个不同材料制成的正方体甲和乙叠放在水平桌面上,已知甲重4N,乙重5N,甲对乙的压强与乙对桌面的压强相等;

一,p1=F1/S1=G1/a'²；p2=F2/S2=(G1+G2)/a''².二,G1/a'²=(G1+G2)/a''².(a'/a'')²=G1/(G1+G2)=4N/(4N+5N)=4/9.a'/a''=2/3(或3a'=2a''）.三,V1/V2=(a'/a'')³=8/27.四,ρ1/ρ2=(m1/V1)/(m...