Your car misses a turn and sinks into a small lake to a depth of 8 m. Your quick mind tells you that the chances of driving out are slim, so you’d better swim for it. The car door, however, is not budging, even though it seems undamaged.

(a) If the outside area of the car door is 0.9 m², what is the force exerted on the door by the water?

(b) What is the force exerted on the inside of the door by the air, assuming atmospheric pressure inside?

(c) What will you have to do to get the door open and save your skin?