>>170
[1] Weight = Volume * Density
Check with units
kg = [m³] * [kg/m³]
>OK. That makes sense
The m³ cancel each other and you have kg = kg
Now check what information you have and what you want.
Weight (OK) = Volume (Incomplete) * Density (Google)
Density of Steel = 8050 kg/m³
[2] Volume (Incomplete) = Area (OK) * Depth (Unknown)
Substitute Equation [2] into Equation [1] and solve for depth
Weight = [Area * Depth] * Density
Weight / (Area * Density) = Depth
>>171
Close enough.