Explained: Relation Between Pressure and Kinetic Energy of Gas

Relation Between Pressure and Kinetic Energy of Gas

BY Team Aakash Byju's

In Physics, pressure is defined as the physical force exerted on a body of definite mass.

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The force applied will be perpendicular to the surface of the object per unit area.

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Hence, we write pressure as P=FA, F is force and A is the unit area and we measure it in terms of pascals (Pa).

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The form of energy that an object has due to its motion is called 'Kinetic energy'.

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In other words, kinetic energy is the amount of work done to accelerate a body from rest to its stated velocity.

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The kinetic energy is expressed as K=1/2mv2, where m is the mass of the body and v is its velocity.

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Do you know how to express the pressure of a gas molecule?

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where ρ is the density and v is the rms velocity of the gas molecule.

Now, please note that the density is nothing but the ratio of mass and volume.

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Substitute the value of mass in the equation for kinetic energy we get.

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If the gas molecule has unit volume (V=1), then

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Divide pressure (P) by kinetic energy (V)

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Thus, P=2/3K and this shows that pressure of a gas molecule is 2/3 of its kinetic energy per unit volume.

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Add these points to your revision notes and share them with your friends.

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