Fig shows a rectangular sluice door $AB$ hinged at A and the sluice is kept closed by

the weight $W.$ The sluice door is $1\mathrm{.}2m$ wide and $0\mathrm{.}9m$ deep. The combined $CG$ of the

door and weight is located at $G.$ The vertical line through $G$ is $0\mathrm{.}3m$ from $A.$

The weight and the sluice door have a combined mass of $1000kg.$ What is the

water depth $h$ which will open the sluice door? $[>0\mathrm{.}88$m$]$