The pressure of the air exerted over a square inch area at the surface of the earth at sea level is?

The pressure of the air exerted over a square inch area at the surface of the earth at sea level is?

• A. 1 atm
• B. 101.3 kPa
• C. 14.7 pounds per square inch
• D. 1 bar

Answer: (C)

At sea level, the air exerts a weight per unit area that defines atmospheric pressure. The standard value is 1 atmosphere, which equals 101.3 kilopascals. When you express that same pressure in pounds per square inch, it comes out to about 14.7 psi. So the pressure over a square inch at sea level is 14.7 psi. (1 bar is close, about 14.5 psi, and 101.3 kPa is the same pressure expressed in kilopascals, but for per-square-inch terms the 14.7 psi value is the direct match.)

At sea level, the air exerts a weight per unit area that defines atmospheric pressure. The standard value is 1 atmosphere, which equals 101.3 kilopascals. When you express that same pressure in pounds per square inch, it comes out to about 14.7 psi. So the pressure over a square inch at sea level is 14.7 psi. (1 bar is close, about 14.5 psi, and 101.3 kPa is the same pressure expressed in kilopascals, but for per-square-inch terms the 14.7 psi value is the direct match.)