Normal atmospheric pressure is 1.013 105 Pa. The approach of a storm causes the height of a mercury barometer to drop by 27.1 mm from the normal height. What is the atmospheric pressure? (The density of mercury is 13.59 g/cm3.)

Respuesta :

Answer:

The atmospheric pressure is [tex]0.97622\times10^{5}\ Pa[/tex].

Explanation:

Given that,

Atmospheric pressure [tex]P_{atm}= 1.013\times10^{5}\ Pa[/tex]    

drop height h'= 27.1 mm

Density of mercury [tex]\rho= 13.59 g/cm^3[/tex]

We need to calculate the height

Using formula of pressure

[tex]p = \rho g h[/tex]

Put the value into the formula

[tex]1.013\times10^{5}=13.59\times10^{3}\times9.8\times h[/tex]

[tex]h =\dfrac{1.013\times10^{5}}{13.59\times10^{3}\times9.8}[/tex]

[tex]h=0.76\ m[/tex]

We need to calculate the new height

[tex]h''=h - h'[/tex]

[tex]h''=0.76-27.1\times10^{-3}[/tex]

[tex]h''=0.76-0.027[/tex]

[tex]h''=0.733\ m[/tex]

We need to calculate the atmospheric pressure

Using formula of atmospheric pressure

[tex]P=\rho g h[/tex]

Put the value into the formula

[tex]P= 13.59\times10^{3}\times9.8\times0.733[/tex]

[tex]P=0.97622\times10^{5}\ Pa[/tex]

Hence, The atmospheric pressure is [tex]0.97622\times10^{5}\ Pa[/tex].