JEE Main 2025 Physics question

A vessel with square cross-section and height of 6 m is vertically partitioned. A small window of 100 cm² with hinged door is fitted at a depth of 3 m in the partition wall. One part of the vessel is filled completely with water and the other side is filled with the liquid having density 1.5 × 10³ kg/m³. What force one needs to apply on the hinged door so that it does not get opened? (Acceleration due to gravity = 10 m/s²)