The pressure of water at bottom in a lake is 32times that at 2 half depth where the water barometer reads 10 m. The depth of the lake is:
15 m
infinite
20 m
10 m
(P0+hρwg)=32P0+h2ρwg hρwg1-34=P02 ⇒ h=P0×42×ρwg=105×42×103×10=20m