(1)圆柱体的重力:G=F=pS;
(2)∵圆柱体漂浮
∴F浮=G
ρ水g[1/2]V=ρ0gV
则
ρ0
ρ水=[1/2];
(3)∵圆柱体和塑料共同漂浮
∴F浮′=G
ρ水g(Sd+[1/2]V+Sh)=ρ0gV+ρgSd
ρ水(Sd+[1/2]V+Sh)=ρ水V+ρSd
则[ρ
ρ水=
Sd+Sh−
1/2V
sd].
故答案为:(1)pS;(2)[1/2];(3)
Sd+Sh−
1
2V
sd.
(1)圆柱体的重力:G=F=pS;
(2)∵圆柱体漂浮
∴F浮=G
ρ水g[1/2]V=ρ0gV
则
ρ0
ρ水=[1/2];
(3)∵圆柱体和塑料共同漂浮
∴F浮′=G
ρ水g(Sd+[1/2]V+Sh)=ρ0gV+ρgSd
ρ水(Sd+[1/2]V+Sh)=ρ水V+ρSd
则[ρ
ρ水=
Sd+Sh−
1/2V
sd].
故答案为:(1)pS;(2)[1/2];(3)
Sd+Sh−
1
2V
sd.