将甲、乙两个完全相同的溢水杯放在水平桌面上,甲溢水杯中装满密度为ρ1的液体,乙溢水杯中装满密度为ρ2

2025-05-03 15:01:29
推荐回答(3个)
回答1:

A、因为物体A漂浮在甲容器中,所以F=GA,即ρ1Vg=ρ1

3
4
Vg=ρVg,由此可得ρ1:ρA=4:3,故A错误;
B、FB浮2gVB=
ρ2gGB
ρBg
=
GBρ2
ρB
=
32GB
45
,FA浮:FB浮=GA
32GB
45
=
3VA
8VB
,不能确定具体比值关系,故B错误;
C、GAAgVA,VA=
GA
ρAg
,p11gh,
p22gh,
p1:p21:ρ2=3:2,故C错误;
D、∵ρ1:ρ2=3:2,ρA:ρ1=3:4,ρA:ρB=4:5,
∴ρ2:ρB=
2ρ1
3
:1.25ρA=
2
3
×
4
3
:1.25=32:45,
GBBgVB,VB=
GB
ρBg
,FB浮2gVB=
ρ2gGB
ρBg
=
GBρ2
ρB
=
32GB
45

F=GB-F B浮=GB-
32GB
45
=
13GB
45

F
GB
=
13
45
,故D正确.
故选D.

回答2:

A、因为物体A漂浮在甲容器中,所以F浮=GA,即ρ1V排g=ρ1
3
4
Vg=ρVg,由此可得ρ1:ρA=4:3,故A错误;
B、FB浮=ρ2gVB=
ρ2gGB
ρBg
=
GBρ2
ρB
=
32GB
45
,FA浮:FB浮=GA:
32GB
45
=
3VA
8VB
,不能确定具体比值关系,故B错误;
C、GA=ρAgVA,VA=
GA
ρAg
,p1=ρ1gh,
p2=ρ2gh,
p1:p2=ρ1:ρ2=3:2,故C错误;
D、∵ρ1:ρ2=3:2,ρA:ρ1=3:4,ρA:ρB=4:5,
∴ρ2:ρB=
2ρ1
3
:1.25ρA=
2
3
×
4
3
:1.25=32:45,
GB=ρBgVB,VB=
GB
ρBg
,FB浮=ρ2gVB=
ρ2gGB
ρBg
=
GBρ2
ρB
=
32GB
45

F=GB-F B浮=GB-
32GB
45
=
13GB
45


F
GB
=
13
45
,故D正确.
故选D.

回答3:

D.F∶GB=13∶45