则 V甲=
m |
5ρ |
m |
3ρ |
∴V甲:V乙=
m |
5ρ |
m |
3ρ |
设甲、乙两物体体积分别为3V、5V.
甲下沉时受到的浮力F甲浮=ρ水g3V,
乙漂浮时受到的浮F乙浮=G乙=ρ乙gV乙=ρ乙g5V,
∵甲、乙两物体受到的浮力之比为4:5,
∴F浮甲:F浮乙=ρ水g3V:ρ乙g5V=1.0×103g3V:3ρg5V=4:5,
解得ρ=0.25×103kg/m3,
∴ρ甲=5ρ=5×0.25×103kg/m3=1.25×103kg/m3,
ρ乙=3ρ=3×0.25×103kg/m3=0.75×103kg/m3;
∵V排甲=V甲,V排乙=
ρ乙5V |
ρ液 |
∴V排甲:V排乙=3V:
ρ乙5V |
ρ液 |
ρ乙 |
ρ液 |
0.75×103kg/m3 |
0.9×103kg/m3 |
故选A.