Ok, 'A circular window with a 30 cm diameter in a submarine can withstand a maximum force of 5.2x10^5N. What is the maximum depth (in m) in a lake to which the submarine can go without damaging the window round off to the nearest whole number?' I tried P=F/A=pAhg/A, so I converted 30 cm to meters, solved for P then tried to find h. p=1000, A=pi*.15^2, h=?, g =9.8. So .070 = 9.8h, h=7.21X10^-6. That can't be right because then the submarine wouldn't move at all before the window busted. Can someone tell me where I went wrong? Thanks!