A watertight car is submerged under water. What force is required to open a door of area 1.12 m2 if the average depth of water at the door is 1.50 m?

Answer 1

It depends on the pressure inside the car. after a few minutes the car will fill with water from holes in the floor etc and only a bubble of air at ambient (water) pressure will remain under the roof (avoid leaky sun roof). At that point the door (or window) will open easily.