如图所示,质地均匀粗细相同的实心圆柱体A、B放在水平地面上.已知它们的密度之比ρA:ρB=1:2,对地面

2025-03-06 12:07:18
推荐回答(1个)
回答1:

(1)∵圆柱体对水平地面的压强:
p=
F
S
=
G
S
=
mg
S
=
ρVg
S
=
ρShg
S
=ρgh,
hA
hB
=
pA
ρAg
pB
ρBg
=
pA
pB
×
ρB
ρA
=
1
3
×
2
1
=
2
3
,故A正确,B不正确.
(2)两圆柱体的粗细相同,对地面压强的受力面积相同,
∵p=
F
S

FA
FB
=
pAS
pBS
=
pA
pB
=
1
3

∵水平面上物体的压力和自身的重力相等,且G=mg,
mA
mB
=
GA
g
GB
g
=
FA
g
FB
g
=
FA
FB
=
1
3
,故C不正确,D正确;
故选AD.