What is the force at sea level that air exerts on?

Question

The atmospheric pressure at sea level is about 1.0 105 Pa. What is the force at sea level that air exerts on the top of a typical office desk, 144 cm long and 78 cm wide?

Answer 1

P = F/A  (i.e. psi = pounds per square inch)

Just multiply the pressure by the area and make sure to convert all of the units.

Answer 2

144 x 78 = 11 232 cm^2 = 112.32 m^2

1 Pa = 1 newton/m^2

Force = Pressure x Area = 1.0 x10^5 N/m^2 x 112.32 m^2

Force on desk = 112.32 x 10^5 Newtons

or about 11 Million newtons