The force acting on a window of area 50 cm x 50 cm of a submarine at a depth of 2000 m in an ocean, the interior of which is maintained at sea level atmospheric pressure is (Density of sea water = 103 kg m-3, g = l0 ms-2)

Here, h = 2000 m, ρ = 103 kg m-3, g = 10 ms-2The pressure outside the submarine is P = Pa+ρghwhere Pa is the atmospheric pressurePressure inside the submarine is Pa.Hence, net pressure acting on the window is guage pressure.Gauge pressure, Pg = P-Pa = ρgh   = 103 kg m-3 × 10 ms-2× 2000 m = 2 ×107 PaArea of a window isA = 50 cm × 50 cm = 2500 × 10-4 m2Force acting on the window isF = PgA  = 2×107 Pa × 2500 × 10-4 m2   = 5 × 106 N