A submarine is cruising at a depth of 250 m below the surface of the water (about the height of 70-floor skyscraper).
a) Taking SGsea-water = 1.03, calculate the absolute pressure at this depth, in Pa. How many times greater than one atmospheric pressure is this value?
b) Convert this calculated pressure (from part a) to psi. Show clear working for obtaining the conversion factor for Pa to psi, using these values: 1 lbf = 4.45 N, 2.54 cm = 1 inch.
c) If the air inside the submarine is at atmospheric pressure, what is the net (or resultant) force (in lbf) acting per square inch of the skin of the submarine? Express this force in terms of the weight of something familiar and comparable, such as an engineering textbook, a person, a passenger car, a school bus, etc.