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 $= 1.01332 × 10^ 5 Pa$