Question

Pressure is determined as force per unit area of the surface. The SI unit of pressure, pascal is as shown below:
\(1\text{Pa} = 1\text{N m}^{–2} \)
If mass of air at sea level is \(1034\, \text{g cm}^{–2}\), calculate the pressure in pascal.

Answer 1

Pressure is defined as force acting per unit area of the surface.

\(P = \frac{F }{ A}\)

\(= \frac{1034 g × 9.8 ms^{-2} }{ cm^2} × \frac{1 kg }{ 1000 g }× \frac{(100)^2 cm^2 }{ 1 m^2}\)

\(= 1.01332 × 10^ 5\, kg m^{-1}s^{-2}\)

We know, \(1 N = 1 kg ms^{-2}\)

Then, \(1 Pa = 1 Nm^{-2}\)

\(= 1 kg m^{-2}s^{-2} 1 Pa = 1 kg m^{-1}s^{-2}\)

∴ Pressure \(= 1.01332 × 10^ 5 Pa\)