Question

急!初二物理题急需解答!1、一只水桶底面积为200cm²,内装100N的水,水的高度为30cm,则桶底所受压强

Answer 1

1、P=ρgh=1000kg/m^3×10N/kg×0.3m=3000Pa

2、塞子要脱落,说明塞子受到水的压力至少为0.5N

P=F/S=0.5N/1×10^-4m^2=5000Pa

h=P/ρg=5000Pa/(1000kg/m^3×10N/kg)=0.5m

即水深0.5m时塞子受到0.5N的压力

此时V水=Sh=1m^2×0.5m=0.5m^3

所以至少加0.5m^3的水