pressure molecular origin

Question

Pressure of gas arises due to:

RankGuru · Accepted Answer

According to the Kinetic Theory of Gases, gas pressure is a macroscopic manifestation of microscopic collisions.
1. **Momentum Change**: When a gas molecule of mass $m$ and velocity $v_x$ hits a wall and rebounds elastically, its momentum changes by $\Delta p = m(-v_x) - m(v_x) = -2m v_x$.
2. **Impulse**: The wall exerts a force to cause this momentum change. By Newton's Third Law, the molecule exerts an equal and opposite force on the wall.
3. **Averaging**: The constant bombardment by billions of molecules creates a steady average force. 
4. **Pressure**: Pressure is defined as this average force divided by the area of the wall ($P = F/A$).

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pressure molecular origin

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