Acircular window 30 cm in diameter in a submarine can withstand a maximum force, exerted by the fluids surrounding it, of 5.20 × 105 n without damage. what is the maximum depth in a fresh-water lake to which the submarine, containing air at atmospheric pressure, can go without damaging the window? the density of fresh water is 1000 kg/m3.

755 m

Explanation:

Given:

Diameter of the window, d = 30 cm

                                            = 0.3 m

Therefore, radius r = 0.15 m

Force, F =

Density, ρ = 1000kg/m3

Thus, Area of the window, A =

                                               =

                                               = 0.07

Therefore pressure, P = Force / Area

                                    = /  0.07

                                    =

We know that, pressure, P = ρ.g.h

where, g is acceleration due to gravity =

            h is depth

Therefore,  P = ρ.g.h

            or h =

                    =

                    = 755 m

Thus the maximum depth is 755 meter.

a and b sometimes have a positive value