Pressure Exerted By Gas Molecules | Statistical Mechanics & Thermodynamics |Chapter 16 | Physics 12

Pressure Exerted By Gas Molecules | Statistical Mechanics & Thermodynamics |Chapter 16 | Physics 12 | National Book Foundation | FBISE #FederalBoard #ModelTownHumak #EducationalChannel #siranjumteaches #nationalbookfoundation 📘 Pressure Exerted by Gas Molecules | Physics Class 12 | Chapter 16 | Statistical Mechanics & Thermodynamics | NBF | FBISE In this lecture, we explain the concept of *Pressure Exerted by Gas Molecules* from Chapter 16 of the Class 12 Physics book (National Book Foundation - FBISE). This topic is part of *Statistical Mechanics and Thermodynamics* and is based on the **Kinetic Theory of Gases**. According to this theory, gas molecules are in continuous random motion and collide with the container walls, exerting pressure. Using Newton’s second law and momentum principles, we derive expressions for gas pressure. 📌 Key Derivations Covered: Force exerted by gas molecules on the container wall: F = Δp / Δt Pressure exerted by one molecule: P = F / A = m * vₓ² / V For N molecules, total pressure becomes: P = (1/3) * (mN / V) * (v²) This gives: P = (1/3) * ρ * v² 📌 Pressure in Terms of Average Translational Kinetic Energy: We relate pressure to the average kinetic energy (K.E) of gas molecules: P = (2/3) * (N/V) * (1/2 * mv²) Hence, P ∝ K.E (avg) 📌 Pressure in Terms of Density: Using ρ = mN / V: P = (1/3) * ρ * v² 📌 Temperature Relationship: Using Ideal Gas Law: PV = NkT or PV = nRT And comparing with the kinetic theory equation: T = (2/3k) * (1/2 * mv²) This shows that *temperature is directly proportional to the average translational kinetic energy* of gas molecules. 📚 This lecture helps students understand how gas pressure arises due to molecular collisions and how it connects with kinetic energy, density, and temperature — all based on textbook diagrams and derivations. 🎓 Ideal for Class 12 Physics (FBISE) students and those preparing for board exams. #GasPressure #KineticTheory #Physics12 #StatisticalMechanics #FBISE #GasLaws #NBFPhysics #TranslationalKineticEnergy #RootMeanSquareSpeed #PVnRT #studywithus #boardexampreparation #MatricFScPreparation #onlinelearningpakistan